Micro Tunneling for Pipeline Installation

What is Micro Tunneling?

Micro Tunneling (M/T) is a process that uses a remotely controlled Micro Tunnel Boring Machine (MTBM) combined with the pipe jacking technique to directly install product pipelines underground in a single pass. This process avoids the need to have long stretches of an open trench for pipe laying, which causes extreme disruption to the community.

Important Features of Micro Tunneling

Micro tunneling is currently the most accurate pipeline installation method. Line and grade tolerances of one inch are the micro tunneling industry standard. This can be extremely important when trying to install a new pipeline in an area where a maze of underground utility lines already exists.

Micro tunneling can be used to install pipes from eight inches (200 mm) to twelve feet (3600 mm) in diameter. Therefore, the definition of micro tunneling does not necessarily include size. The importance of trenchless pipe jacking for the laying of supply and disposal conduits and for replacing pipes is growing continuously.

Importance of Micro Tunneling in the Oil Industry

Increasingly, the existing technologies are failing to install new pipelines in demanding oil fields and rough terrains. This happens due to:

High groundwater
Difficult ground condition. (E.g. Mountains – situated nearby many oil fields, rocky ground, perennial rivers, etc.)
Ground with Mixed Gravel

While drilling in gravel with the present HDD technique, the chances of ground collapse are high. So, in this case, no drilling is possible through HDD.

Solution for all the above-mentioned problems – MICRO-TUNNELING

Advantages of Micro Tunneling

Reduced disruption of the community
Reduced liability for personal injury and property damage
Increased service life and asset value for the utility owner
Increased worker safety
Reduced restoration costs
Precise installation
Wet Conditions/Marine Crossings: often the only option
The faster rate of progress than the convention
A reduction of earth movement to a minimum
Consideration of residents and the environment
Lowering of groundwater is unnecessary
Minimal influence on traffic

Wherever horizontal directed drilling technology (HDD) cannot be used:

for difficult and rough gravel soils,
soils with erratic blocks,
in city centers,
where there is no space to extend and retract,

Micro tunneling methods are a true alternative.

Shaft/Well Construction

Construction of a Shaft / Well is one of the primary jobs for carryout Micro Tunneling.

Purpose: To get a safe working platform under the desired depth.

Bottom Plugging

Plug the bottom of the shaft with Reinforced Cement Concrete using a concrete box with the help of divers and a crane. Additives are used to prevent the cement from dissolving in water and increase the plasticity of the concrete for achieving a better flow of concrete into the cutting edge.

After successful bottom plugging the shaft is ready for Micro Tunneling work.

Micro Tunneling Machine(Fig. 1)

Examples of Micro-Tunneling Equipments — **Fig. 1: Examples of Micro-Tunneling Equipment**

Micro Tunneling Method (Fig. 2)

Micro tunneling is a high-performance and environmentally friendly alternative to pipeline construction with trenches; it can also be used in the most demanding of circumstances: groundwater and difficult geologies are no problem for micro tunneling, and it has proven to be a very good method of avoiding obstructions in city centers.

**Fig. 2: Schematic Representation of Micro-Tunneling Method**

The cutter head (1) removes with its tools – cutters, knives, chisels, or discs – the surrounding soil. This is taken to the crusher chamber (2). This is where any stones are crushed (3). Water is initially pumped into the crusher chamber in a closed circuit, mixed with the soil there, and then pumped back out of the drill hole.

The separating system then separates the water from the soil. The soil is disposed of and the water is pumped back into the crusher chamber. The pipe is pushed into the soil using the hydraulic cylinders in the jacking frame. A laser beam dictates the location of the pipe axis. The target board (4) reports the position of the laser point to the machine operator in the control container. Hydraulic cylinders (12) mean that the cutter head can be angled, thus correcting the position. The operator controls the entire system from the control container.

Pipe Jacking Method

Pipe Jacking is a method of Tunnel Construction where hydraulic Jacks are used to push especially made pipes through the ground behind a tunnel boring machine or shield. The method provides a flexible, structural, watertight finished pipeline as the tunnel is excavated.

Pipe jacking utilizes a jacking device to push pipe horizontally into the ground, forming a continuous string of pipe. Material is excavated as the pipe is pushed in. A thrust wall is constructed to provide a reaction against the jack. High-pressure jacks provide the substantial forces required for jacking concrete pipes.

Pipe jacking is an economical alternative to and much less disruptive than using open-cut construction to install new underground pipes. Because it is performed with a closed system, pipe jacking decreases the risk of environmental contamination during construction.

Jacking Frame (Fig. 3)

The jacking frame is the main device that plays a vital role in Pipe jacking. The pipe is pushed into the soil using the hydraulic cylinders in the jacking frame.

Inter jack (Fig. 3)

An inter-jack station is a ring of hydraulic jacks within a steel framework that is inserted into the pipe string at strategic points. Each inter jack divides the pipe string into more manageable jacking lengths. Each length, whether between jacking frame and inter jack, inter jack and inter jack, or inter jack and face, can be advanced individually and independently from the rest of the pipe string. It is the equivalent of having several smaller pipe jacks in operation at the same time in one bore, with each inter jack using the pipe length behind it as its thrust wall.

The use of inter jack reduces the potential for pipe failures since the maximum force on any individual ‘sub-string’ depends on the number of pipe sections plus the friction factor over that length of pipe. Each inter jack is controlled independently from the operator’s station and can, where necessary, be individually lubricated with the correct control and lubrication pump set-up.

ELS (Electronic Laser System) Control system for pipe jacking

In order to recognize the position of the Tunnel Boring Machine (TBM) (horizontal and vertical deviations, the pitch and roll tendency of the machine, and the yaw angle) suitable sensor technology is necessary to guide a TBM. ELS is an intelligent sensor unit with a sturdy metal case. The device is roughly the size of a shoebox and is watertight up to 5 meters submersion. It is dry-filled with an inert gas under slight pressure. The ELS is installed on the back of the tunneling machine so that the guidance laser makes contact with the target. The device is connected via a cable that supplies the power and transmits the measurement results.

Bentonite / Micro tunnel Lubrication Units

Designed primarily for the mixing and pumping of Bentonite and Polymers used as lubricants for Microtunnel and Pipejack construction, the Concrete Eurodrill range of Microtunne Lubrication Units (MLUs) offer complete systems including mixers, storage tanks, and injection pumps to meet a variety of requirements. They all incorporate the well-proven Colcrete Colloidal Mixer, which produces a very stable product, which resists water separation and retains its lubrication properties for longer when injected. A variety of pumps can be fitted, usually based on well-proven grout pumps such as the Mocol and Minicol ranges.

JACKING PIPES

Micro tunneling techniques require the jacking of a pipe into the ground using often high jacking forces, the correct choice of pipe with the ability to withstand the required jacking forces during installation and the right properties in terms of final product performance is as important as choosing the right machine to install it in the first place.

A wide range of pipe materials is available for installation using pipejacking and micro tunneling techniques, the choice depending on the requirements of the client, the ground conditions, transportation costs, and the length of the pipeline. Materials including reinforced and un-reinforced concrete, polymer concrete (concrete aggregate within a matrix of resin), glass fiber/resin-based pipes, vitrified clayware (both glazed and unglazed), steel, ductile iron, and also plastics are available as jacking pipe. In the majority of cases, the pipe material is either concrete or clayware, manufactured for pipe jacking to strict standards.

Separation Plant

The separating system separates the water from the soil. The soil is disposed of and the water is pumped back into the crusher chamber.

Different soil conditions – Different M/T Machine

Rocks: Modern technology offers new, uncomplicated options even when drilling through rocks with high degrees of hardness. In places that previously required detonation or mortise work, micro tunneling is now seen as a reliable alternative.

Stones and erratic blocks: Innovative technology creates new options: The use of mixed drill heads, which are fitted with knives and cutters for cohesive soils, as well as chisels and discs that can crush erratic blocks or rock layers, means that even the most difficult of soils can be drilled.

Flowing soils: Soil-aligned apertures in the cutter head mean that the soil excavation can be adjusted to suit the mass required by the pipe displacement.

Special Areas of Use: You can reap the rewards of micro tunneling, especially in demanding areas: no river is too broad, and no water is too deep.

River Crossings: River tunnels with excavations are largely a thing of the past. Even the broadest currents can be crossed safely using micro tunneling.

Overview of Construction Site (Fig. 4)

Online Video Courses related to Pipeline Engineering

If you wish to explore more about pipeline engineering, you can opt for the following video courses

Few more Pipeline related useful Resources for You..

Underground Piping Stress Analysis Procedure using Caesar II
Comparison between Piping and Pipeline Engineering
A Presentation on Pipelines – Material Selection in Oil & Gas Industry
Corrosion Protection for Offshore Pipelines
Start up and Commissioning of the Pipeline: An Article
DESIGN OF CATHODIC PROTECTION FOR DUPLEX STAINLESS STEEL (DSS) PIPELINE
AN ARTICLE ON MICRO TUNNELING FOR PIPELINE INSTALLATION
A short presentation on: OFFSHORE PIPELINE SYSTEMS: Part 1
Factors Affecting Line Sizing of Piping or Pipeline Systems

Piping Stress Analysis Specification | Flexibility Specification

Written by Anup Kumar Dey in Piping Stress Analysis,Piping Stress Basics

Every Organization prepares its own piping stress analysis specification or flexibility specification to cater as a guideline for stress analysis of critical lines and for uniformity of jobs performed by pipe stress engineers. From project to project, this specification may vary slightly but overall the contents are almost similar. In this article, I will explain the points which must be addressed/ included while making a flexibility specification.

Scope/Purpose of Flexibility Specification:

All engineering documents must inform their end-user what the content is all about and must start with Scope or Purpose. This part document will supply information about how the user will be benefited from the document. What is the purpose of preparing the document? What points are covered in the document and which points are excluded?

Abbreviations and Definitions:

Mention the detailed names of abbreviated terms. Definitions are also required to provide in this section.

Reference Documents:

In this section, the specification will inform the references used for making the specification. The Specification will list all the codes and standards, in-house work instructions, or specifications that will be used in the project.

Criteria for Stress Analysis:

This part mentions the minimum criteria which have to be adhered to while performing pipe stress analysis. Code equations that need to be followed etc.

Stress Critical line list:

This section mentions the criteria for deciding stress critical lines. The factors like line size, temperature, equipment connection, etc force the stress engineer to consider the system for stress analysis using Caesar II software.

Analysis Software:

This section mentions which pipe stress analysis software (Caesar II, Start-Prof, AutoPIPE, CaePIPE, Rohr2, etc) to use for that specific project. The version of the software must be included. It is always better to perform the analysis with the latest version of the software.

Analysis Parameters: In this point explain the required parameters for analysis like:

Installation temperature: Mention the installation or ambient temperature of the location where the project site is.

SIF for 45-degree branch connections: Inform the engineers to use any specific criteria for calculating SIF for 45-degree branch connections.

PSV Reaction Force: Inform the engineer how to calculate the PSV reaction forces. Any dynamic load factor if needed to be used.

Slug Loads/Two-Phase flow: Inform if any specific requirement is there for two-phase flow lines like the frequency of the system needs to be maintained above 4-5 Hz, for Slug flow if dynamic analysis to be performed, etc.

Wind Loads: Mention the criteria for wind loads (what’s the size), what shape factor to consider, which code to follow and parameters to be used etc.

Seismic Loads: The criteria, code for seismic analysis, what’s the seismic co-efficient, etc.

Tank Settlement: if any tank settlement value has to be considered for analysis of tank piping. Settlement data is normally obtained from the Civil Department from the soil investigation report.

Friction Effects: What will be the friction coefficient for various contact surfaces?

Displacements of Tie–in Points: Criteria for consideration of tie-in points and battery limit conditions.

Thermal Displacements of Equipment: If the equipment is to be modelled or displacement values to be used.

Support Lift Off: Any criteria for hot sustained checking or using ALT Sustained cases as per B 31.3?

Insulation Density: Any guideline for the value of piping insulation density throughout the project.

Pipe Sagging: The accepted value of pipe sagging in sustained case. For example for process lines 10 mm and for flare and steam lines 3 mm.

Flange Leakage Checking: Criteria and method for flange leakage checking if any.

Allowable Nozzle Loads: If any multiplication factor is to be used along with standard allowable nozzle loads. For example twice API 610 values for Centrifugal Pumps, 3 times API 617 for Centrifugal compressors, and Twice API 661 for Air Fin Coolers etc.

WNC Checking: Criteria for alignment/anchor-free analysis and accepted displacement values if any for rotary equipment. If springs are to be kept in an unlocked condition.

Modelling Criteria: If guide and line stop to be modelled without friction and gap if any density is to be considered for flare headers during modelling etc.

Stress Analysis Documentation: In this section briefly describe which reports (For example input echo, restraint summary, stress summary, etc.) are to be submitted to clients as the final stress analysis document of each stress system.

Any guidelines for supporting the piping system?

The above points are the minimum required points. Additionally, you can add many more points depending on the project requirements. So, hopefully, by now you will be able to produce the flexibility specifications of your own.

START-PROF Piping Stress Video Training Series [In-Depth]

Written by Alex Matveev in Piping Stress Analysis,Start-Prof

Before starting this video series let tell you some basic idea of Pass/Start-Prof.

What is PASS/START-PROF?

Piping And Equipment Analysis & Sizing Suite or PASS/START-PROF is a comprehensive pipe stress analysis program similar to other Stress Analysis software like Caesar II, AutoPipe, Caepipe, Rohr II, etc. PASS/START-PROF software checks the piping flexibility, stability, and fatigue strength at ease. It performs all related sizing calculations following international and national codes & standards.

It is the world’s first Pipe Stress Analysis Software and first developed in 1965 in Russia. It possesses a highly powerful analysis features and efficient solver with user-friendly 3D graphics. At the same time, their detailed help system from generations of piping design experts is really praiseworthy.

The aim of PASS/START-PROF software creation is that it is planned for regular designers without special knowledge in pipe stress analysis and/or detailed knowledge of standards.

Uses of START-PROF:

PASS/START-PROF can be used to analyze piping and pipeline systems from the following industries:

process piping industry
power piping industry
gas and oil transportation industry
district heating piping
hot water supply etc,

The software can be used for stress analysis of underground, above ground, vacuum, high pressure and/ or high temperature, also cryogenic piping considering various types of restraints, spring hangers, pipe fittings, and expansion joints. PASS/STARTPROF offers an automatic selection of variable and constant spring hanger supports.

The material database of PASS/START-PROF is wide considering the various range of materials that are used in pipelines which include all types of steels, nonferrous materials, plastic pipes and fittings, orthotropic materials such as fiberglass, reinforced plastic, glass-reinforced plastics, and glass-reinforced epoxy.

This video series is created by PASS distributor in Australia – Moonish Engineering

VIDEO 1: How to Create New Project in Start Prof

To access all other tutorial videos simply click on the next mentioned below!

What is a Restriction Orifice (RO)? Its Applications, Types, Working, and Sizing

Written by Anup Kumar Dey in Instrumentation,Piping Design Basics,Piping Interface

A restriction orifice is a device designed to control the flow of fluids by introducing a deliberate constriction in the flow path. It functions by reducing the diameter of the pipeline at a specific point, which results in a pressure drop and flow restriction. Typically, a restriction orifice is a simple, plate-like device with a precisely machined hole, but its impact on the flow characteristics of a system is substantial. In this article, we will describe the significance of restriction orifices, their functionality, working, types, applications, standards, and steps for their design.

What is a Restriction Orifice (RO)?

Restriction orifice or RO, in short, is a flow control instrument device whose primary function is to provide a restriction to the flow so that a controlled or restricted flow is achieved. Due to this restriction by the orifice plate, a pressure head drop from the upstream of the orifice to the downstream is observed. For a specific temperature and pressure condition, the orifice area at the outlet determines the volumetric flow rate of the fluid inside the pipe. Due to the high-pressure drop at the restriction orifices, it can create acoustic-induced vibration. Hence, studies must be performed by specialists.

The orifice plate is basically a thin plate with an orifice in the middle. The plate is inserted between two flanges of a pipe for providing restriction or flow measurement.

Purpose of Restriction Orifice

Restriction Orifice is used primarily for two main reasons:

If there is a requirement for Reduced flow or
If there is a requirement for high-pressure drops.

The device is sized depending on the required pressure drop. They are designed to slip between the piping flanges. Restriction orifice comes with single restriction orifices or multiple restriction orifices in Series.

How Restriction Orifices Work?

The fundamental principle behind a restriction orifice is based on fluid dynamics. When a fluid flows through a constricted area, its velocity increases, and its pressure decreases. This is described by Bernoulli’s equation. By selecting an orifice of appropriate size and shape, engineers can precisely control the flow rate and pressure drop across the orifice. It is calibrated based on the installation’s technical requirements to achieve the correct pressure or flow rate. Depending on the needed values, either simple restriction orifices (with one or multiple holes) or multi-stage restriction orifices can be used.

Applications of Restriction Orifice

Engineers and designers are familiar with a restriction orifice in the following applications for impeding flow or reducing pressure.

They are installed downstream of blowdown valves to ensure a controlled flow rate in the blowdown piping or blowdown header.
They are installed in the minimum flow bypass lines around centrifugal pumps.
They are installed in Wellhead applications
A restriction Orifice is sometimes used to restrict excess flow in case ruptures.
Minimum bypassing
Injection, cooling, and flushing of fluid.
Sampling.
The steam let down.
Use as a simple static mixer
N₂ purge or constant gas seal
Controllability improvement

Restriction Orifice Standard

There is no direct standard addressing the design of restriction orifice, but some associated references are available as listed below:

ISO 5167 Part 1 and Part 2
ISA RP 3.2
API -RP 550/551
API 2531
IEC 60534-8-3
API Manual of Petroleum Measurement – Chapter 4
AGA Report No.3
API MPMS 14.3.2
ISO 5024
ISO 5168

Working Principle of Restriction Orifice/Orifice Plate

Both Restriction Orifice and Orifice plate work following Bernoulli’s principle that states that pressure drops across the restriction orifice are directly proportional to the volumetric flow rate passing through the orifice plate.

While fluid flows through the plate, fluid velocity changes that in turn, as per Bernoulli’s equation change the pressure. This change in pressures upstream and downstream is measured to calculate the volumetric flow rate.

Restriction Orifice Types

Restriction Orifice Plates are of three types

Single-Stage Restriction Orifice:

A plate with an orifice bore of the required size for intended pressure loss is known as a single-stage restriction orifice.

Multi-hole Single Stage Restriction Orifice:

To reduce the noise generated, single-stage multi-hole restriction orifice plates are used. As the high-velocity flow at the RO inlet is distributed through several holes, the noise is reduced. To avoid the cavitation problem, multi-hole restriction orifices are used. The flow distribution through multiple holes improves the cavitation factor which in turn reduces the overall noise.

Multistage Restriction Orifice Assembly:

Multistage restriction orifices are widely used for very high-pressure reduction when a single-stage RO is not capable. It consists of a number of single-stage RO devices. The design can be single-hole or multi-hole. The restriction orifices in a multistage RO are usually arranged in an eccentric manner. The minimum distance between each stage is usually the internal diameter of the pipe.

Types of Orifice Plates:

The plates used in restriction orifice design can be of the following types:

Square edge bore or standard bore orifice plate.
Quadrant edge bore
Eccentric bore orifice plate
Segmental bore orifice plate
RTJ-type orifice plate with an integral gasket
Paddle-type orifice plates

Inputs for Restriction Orifice Design

The following inputs are required for the design of the restriction orifice:

PFD and P&ID
Hydraulic Calculation Sheet
PMS
Line operating conditions like upstream-downstream pressure, temperature, flow rate, line size, Density, Viscosity, molecular weight, Cp/Cv, vapor pressure, etc.

Restriction Orifice Design Steps

Based on the service and requirements, RO needs to be sized for critical or pre-critical conditions. During sizing, the pressure control RO plates consider the maximum pressure drop lesser than the critical pressure, and flow control RO plates consider the critical pressure drop. ISO 5167 is generally followed for sizing restriction orifices.

The design of the Restriction orifice or RO is carried out as per the steps similar to as mentioned below:

Determination of Application
Data Preparation for the orifice
Restriction orifice sizing (by design engineer or vendor)
Checking of critical design elements like cavitation index (Kc=0.93), pressure drop, minimum orifice diameter, allowable space in piping routing, etc.
Filling out the necessary information in P&ID and RO datasheets

Installation of Restriction Orifice

The restriction orifice is physically a thin plate with one or more holes in it. In piping application, They are normally inserted in between two flanges. It is possible to inadvertently leave out the plate when the piping is assembled, or, more likely, to forget to replace it when the piping is reassembled, following maintenance or cleaning. So leaving out the orifice is difficult.

Restriction Orifices — **Restriction Orifice Types**

Safe solution

To prevent this, one should make it impossible to assemble or reassemble the piping without including the orifice. A simple, practical, and foolproof method are: the restriction orifice has its own spool piece. So in such a situation, there will not be scope for forgetting the RO element during installation or Construction.

Orifice upstream and downstream requirements

It is a standard engineering practice to keep 10 pipe diameters (10D) upstream (before the orifice) and 5 pipe diameters (5D) downstream of the restriction orifice.

Restriction Orifice Symbol

The following symbols are used in P&ID to describe restriction orifice and orifice plates.

Restriction Orifice vs Orifice Plate

The major differences between the Restriction orifice and orifice are tabulated below:

	Restriction Orifice	Orifice
Purpose	A restriction Orifice is used for killing the high pressure or reducing pressure; a pressure-reducing device.	An orifice is used for flow measurement.
Hole Profile	The hole of the restriction orifice has a straight profile	The hole profile of the orifice is straight at first but then beveled (notched) with a 45° slope
Pressure Drop	Restriction Orifice causes High-Pressure drop	The pressure drop in a normal office is low.
Fluid Velocity	Restriction orifices work on sonic Velocity to ensure choked flow.	The flow through the orifice is a subsonic flow.
Acoustic Induced Vibration	Restriction Orifice is highly Susceptible to AIV and high noise can generate	Flow through usual orifice plates is not Susceptible to AIV.

Table: Difference between Orifice and Restriction orifice

Factors for Sizing RO device

There are various factors that must be considered while sizing restriction orifice.

Pressure Drop:

For sizing and selecting the restriction orifice, the pressure drop is a critical parameter. The required minimum thickness of a RO device is dependent on the pressure drop across the device.

Flow Rate:

As the pressure drop is dependent on the flow rate changes, the restriction orifice needs to be sized for a normal flow rate. For critical RO, the downstream flow rate should be considered.

Sonic Flow:

Choked or sonic flow conditions may arise due to a decrease in density and an increase in velocity when a gas accelerates through a restriction. A Sonic flow in the pipeline generates high noise and vibration in the pipeline that may cause mechanical failure. To avoid this, the maximum pressure drop across a single-stage restriction orifice plate must be limited to a critical pressure drop.

Cavitation:

In liquid flow restrictions with very large pressure drops, cavitation may occur. While passing through the restriction orifice, the velocity of liquid drops, and pressure increases. Due to these, vapor bubbles can collapse and flashing can occur. this phenomenon is known as cavitation. To avoid cavitation, the restriction orifice should be sized to maintain the cavitation index less than the incipient cavitation index of the RO plate. Inlet pressure, outlet pressure, and vapor pressure are the parameters for the cavitation index, and the incipient cavitation factor will be dependent on the beta ratio of the plate.

Noise Level:

Noise levels in RO can be predicted by calculating sound power generated due to pressure reduction. Next, the transmission losses can be subtracted to find the sound level at any pre-decided location. To reduce the noise in the restricted orifice, the following options can be selected when sizing.

Reduction of the pressure drop.
Increase the number of stages of reduction.
Using multi-hole RO plates.
Optimizing the pressure drop across each stage.
Increasing the margin between the cavitation index and incipient cavitation index.

Click here to know the sizing procedure of restriction orifices for single-phase fluids

Reference: CHEMICAL ENGINEERING/ APRIL 13, 1987

About the Author: Part of this article is written by Mr. Amir Razmi, an International, dynamic, and multi-functional chemical engineer with 16+ years of experience in engineering and EPC of oil and energy projects from pre-contract activities to execution, and closeout.

Carbon Monoxide Poisoning: Sources, Signs & Symptoms, Prevention

Written by Anup Kumar Dey in Health & Safety

Carbon monoxide (CO) is a colorless, odorless, and tasteless toxic gas that exists in minute concentrations in the atmosphere, typically less than 0.001%. Despite its seemingly benign presence, carbon monoxide poses a significant threat to human health and safety. In 2020 alone, there were 200+ reported deaths attributed to carbon monoxide poisoning, underscoring the urgent need for awareness and preventive measures.

What is Carbon Monoxide Poisoning?

Carbon monoxide poisoning is a medical condition that occurs when an individual inhales an excessive amount of carbon monoxide (CO) gas, leading to its accumulation in the bloodstream. This harmful gas is produced as a result of the incomplete combustion of carbon-containing materials, such as wood, gasoline, natural gas, and other fossil fuels. Carbon monoxide has a high affinity for binding with hemoglobin in red blood cells, forming carboxyhemoglobin (COHb) and preventing oxygen from binding to hemoglobin. This reduces the blood’s ability to transport oxygen to body tissues, which can lead to a range of symptoms and, in severe cases, can be life-threatening. Symptoms of carbon monoxide poisoning can include headaches, dizziness, nausea, vomiting, weakness, confusion, and, at high levels of exposure, unconsciousness or death. Immediate treatment typically involves removing the affected person from the source of carbon monoxide and administering oxygen therapy to restore oxygen levels in the bloodstream.

Carbon monoxide poisoning occurs when individuals are exposed to elevated levels of CO gas. The insidious nature of this poison lies in its stealth – it cannot be seen, heard, or smelled, rendering it devoid of warning signs. This silent killer is a byproduct of the incomplete combustion of carbon-based materials, such as kerosene, natural gas, wood, coal, gasoline, and more. When combustion occurs with insufficient oxygen, carbon monoxide is generated, further emphasizing the need for vigilance.

Sources of Carbon Monoxide in the Workplace

One may be exposed to unsafe levels of Carbon Monoxide in workplaces by:

poor industry maintenance or unvented heating equipment;
poorly vented natural gas burning equipment;
vehicles in garages (car engine exhaust fumes) or other enclosed spaces;
during a plant fire (smoke from fires); etc.

Other sources may include the use of charcoal fire grills in confined spaces (e.g. tents). Poorly installed domestic gas heating appliances and incomplete combustion of butane and propane (e.g. in caravans) may lead to sub-acute, chronic, or occult poisoning.

Some of the sources of carbon monoxide are:

Generators
Concrete cutting saw
Welding fumes
Clogged chimney
Gas heaters
Corroded or disconnected water heater vent pipe

For example, assume that one man is working in a small enclosed non-ventilated room with a fired heater, and complaining of dizziness, severe headache, nausea, weakness, angina is chest pain. He is a patient with Carbon Monoxide poisoning.

Signs and Symptoms of Carbon Monoxide Poisoning

Carbon monoxide (CO) poisoning can present with a range of symptoms, and the severity of these symptoms can vary depending on the level and duration of exposure. Breathing CO can cause headaches, dizziness, vomiting, and nausea. If CO levels are high enough, one may become unconscious and even die. Exposure to moderate and high levels of CO over long periods of time has also been linked with an increased risk of heart disease. People who survive severe CO poisoning may suffer long-term health problems. Sleeping or drunk people can even die from carbon monoxide poisoning before showing any symptoms.

Here, we’ll explain the top 5 symptoms of carbon monoxide poisoning in detail:

Headaches:

Headaches are one of the most common and early symptoms of CO poisoning. These headaches can be persistent, throbbing, and often described as more intense than regular headaches. They are a result of the reduced oxygen supply to the brain due to the binding of carbon monoxide to hemoglobin, which diminishes the brain’s access to oxygen.

Explanation: When CO binds to hemoglobin in the blood, it forms carboxyhemoglobin (COHb), which reduces the blood’s oxygen-carrying capacity. This reduced oxygen delivery to the brain can lead to headaches.

Dizziness and Lightheadedness:

Individuals exposed to elevated levels of carbon monoxide often experience dizziness and a sensation of being lightheaded. This can make them feel unsteady on their feet and affect their coordination.

Explanation: Reduced oxygen supply to the brain impairs cognitive function and balance, leading to dizziness and lightheadedness.

Nausea and Vomiting:

Nausea and vomiting are common symptoms of CO poisoning. The sensation of nausea can be intense and may lead to vomiting. These symptoms are often mistaken for gastrointestinal issues.

Explanation: CO poisoning can affect the gastrointestinal system and trigger nausea and vomiting. These symptoms can further contribute to dehydration, as affected individuals may not be able to keep food or fluids down.

Weakness and Fatigue:

Carbon monoxide poisoning can result in an overwhelming sense of weakness and fatigue. Even minor physical or mental exertion may feel exhausting.

Explanation: Reduced oxygen levels in the blood can lead to muscle weakness and an overall feeling of tiredness and fatigue. This can make everyday activities challenging.

Confusion and Altered Mental State:

As CO levels rise in the bloodstream, it can impair cognitive function and lead to confusion, memory problems, difficulty concentrating, and changes in behavior or mood. In severe cases, it can even cause loss of consciousness.

Explanation: The brain relies on a consistent supply of oxygen to function properly. When CO interferes with oxygen transport, it can lead to a range of cognitive and behavioral changes.

It’s crucial to recognize these symptoms and seek immediate medical attention if carbon monoxide poisoning is suspected. The longer the exposure continues, and the higher the CO levels in the bloodstream, the more severe and life-threatening the symptoms can become. Early detection and treatment with oxygen therapy are vital to prevent serious complications or fatalities related to CO poisoning. If you suspect CO exposure, evacuate the area, get to fresh air, and seek medical help promptly.

The following table in Fig. 2 shows the effects of carbon monoxide exposure levels in the air.

Who is at Risk from Carbon Monoxide Poisoning?

All people are at risk for carbon monoxide poisoning. The elderly and people with chronic heart disease or respiratory problems are generally more at risk than others. In the condition of carbon monoxide poisoning, the patient must be moved away from the CO source to fresh air immediately. In an emergency room, oxygen therapy is the main treatment for carbon monoxide poisoning.

Regulatory Measures for Workplace Safety

Recognizing the gravity of occupational carbon monoxide poisoning, regulatory measures are imperative to safeguard workers. These measures should encompass comprehensive awareness programs, stringent maintenance standards, and proper ventilation protocols in workplaces where CO exposure is a potential risk.

What are the Potential Long-term Effects of Carbon Monoxide Poisoning?

Carbon monoxide (CO) poisoning can have lasting and potentially severe long-term effects, especially if the exposure was significant or went untreated. Some of the potential long-term effects of carbon monoxide poisoning include:

Neurological Symptoms: CO poisoning can cause lasting neurological issues, including memory problems, difficulty concentrating, and changes in behavior and mood. These cognitive deficits can persist for an extended period after the initial exposure.
Psychiatric Symptoms: Individuals who have experienced CO poisoning may be at an increased risk of developing psychiatric symptoms such as depression, anxiety, and post-traumatic stress disorder (PTSD).
Headaches: Chronic, recurring headaches can be a lingering symptom of CO poisoning. These headaches may persist long after the initial exposure.
Fatigue: Many people who have survived CO poisoning report persistent fatigue and a general sense of weakness, which can interfere with daily functioning.
Balance and Coordination Issues: Some individuals may experience difficulties with balance and coordination, which can affect mobility and daily activities.
Visual and Auditory Disturbances: Vision problems, such as blurred or double vision, as well as hearing issues, can occur as a result of CO poisoning.
Cardiovascular Effects: Long-term exposure to CO has been associated with an increased risk of heart problems, including an elevated risk of heart disease.
Respiratory Problems: CO exposure can lead to respiratory issues, such as chronic coughing and shortness of breath, especially in individuals with preexisting lung conditions.
Movement Disorders: In some cases, CO poisoning can result in movement disorders, including parkinsonism, chorea, and choreoathetosis.
Peripheral Neuropathy: Peripheral neuropathy, which involves damage to the peripheral nerves, can lead to tingling, numbness, and weakness in the extremities.

Uncommon complications of carbon monoxide poisoning include well-defined neurological conditions such as:

Parkinsonism, chorea, and choreoathetosis (which correlate with lesions of the putamen and globus pallidus seen on computed tomography and magnetic resonance imaging)
cortical blindness
mutism
hemiplegia
peripheral neuropathy.

Mechanisms of CO Toxicity

CO reduces oxygen delivery to tissues in several ways:

It combines with hemoglobin to form carboxyhemoglobin (COHb), reducing the amount of hemoglobin available to carry oxygen (CO has 240 times the affinity of O₂).
The formation of COHb shifts the oxyhemoglobin dissociation curve to the left, impairing the liberation of oxygen to the cells.
CO binds to myoglobin and cytochrome oxidases (particularly cytochrome a and cytochrome a3) and may impair their ability to utilize the oxygen they receive.
Tissue oxygenation, particularly in vulnerable organs such as the brain, may be further impaired if poisoning is complicated by peripheral circulatory failure. Lipid peroxidation results.

How long does Carbon Monoxide Poisoning Last?

The duration and severity of carbon monoxide (CO) poisoning can vary significantly depending on several factors, including the level and duration of CO exposure, individual health, and promptness of treatment. CO poisoning can be categorized into three general phases:

Acute Phase: This phase occurs shortly after exposure to high levels of carbon monoxide. Symptoms such as headaches, dizziness, nausea, and confusion can manifest within a few hours of exposure. In mild cases, these symptoms may resolve once the affected individual is removed from the CO source and exposed to fresh air. However, in more severe cases, symptoms can progress to loss of consciousness and death within hours.
Intermediate Phase: In some cases, individuals who initially recover from acute symptoms may experience a delayed recurrence of symptoms, known as the intermediate phase. This can occur within hours to days after the initial exposure. Symptoms may reappear or worsen and can include neurological problems, cognitive deficits, and behavioral changes.
Chronic Phase: Chronic or long-term effects of CO poisoning can persist for weeks to months after the initial exposure. These effects may include persistent neurological and cognitive symptoms, mood disturbances, and fatigue. Some individuals may continue to experience health problems for an extended period, while others may recover more quickly.

How to Avoid Carbon Monoxide Poisoning?

Avoiding carbon monoxide (CO) poisoning is essential for your safety and the well-being of those around you. Here are some important steps and precautions to help you prevent CO exposure:

Install Carbon Monoxide Detectors
Regularly Test and Maintain Detectors
Proper Ventilation
Minimize the Use of Gas-Powered Equipment
Properly Maintain Equipment and Appliances
Regular Inspections
Educate all staff
Stay Informed about CO safety.

Few more useful resources for you…

What is Engineering Process Safety?
Safety Rules during A Field Visit By A Design Engineer
An article on Crane safety during Construction
HAZOP (Hazard and Operability) Study: A brief introduction
An article on Excavation Hazards at Construction Sites
Hazardous Area- Theory, Classification and Equipment selection: A short presentation
An article on THE HAZARDS OF PRESSURE TESTING

About the Author: The author of part of this article is Mr. Amir Razmi, an International, dynamic, and multi-functional chemical engineer with more than 17 years of experience in engineering and EPC of oil and energy projects from pre-contract activities to execution, and closeout.

What is Indian Boiler Regulation (IBR)? ASME B31.1 vs IBR

Written by Anup Kumar Dey in Engineering Materials,Piping Design Basics

The Indian Boiler Regulations (IBR) are a crucial set of standards that ensure the safe and efficient operation of boilers and pressure vessels in India. Designed to protect life, property, and the environment, these regulations are a cornerstone of industrial safety and operational excellence. The IBR applies to all industries, both public and private, that use boilers. This includes sectors involved in various processes, heating, and power generation.

What is IBR (Indian Boiler Regulation)?

The Indian Boiler Regulation, or IBR, is an independent body that provides boiler manufacturing guidelines in India and regulates them. Indian Boiler Regulation falls under the IBR Act 1950. This law is accepted all over India except Jammu & Kashmir. The IBR is basically a construction code that specifies the design, material, fabrication, inspection, and testing requirements for boiler and boiler-connected parts for use in India.

The Indian Boiler Regulations (IBR) set standards for the materials, design, construction, inspection, and testing of boilers and their components in India. These standards are developed and regularly updated by the Central Boilers Board to keep pace with advances in boiler technology.

Manufacturers of materials and components used in boilers, such as piping, mountings, fittings, and valves, must adhere to the Indian Boiler Regulation of 1950 (IBR). The IBR also covers:

Steam receivers,
Steam separators,
Steam traps,
Accumulators and similar vessels
Heat exchangers,
Converters,
Evaporators and similar vessels in which steam is produced

The IBR is enforced by the Indian government, and any imported materials or equipment must come with a certificate proving compliance with these regulations. This certificate must be issued by an authorized inspecting authority designated by the Indian government.

IBR or Indian Boiler Regulation Scope

The Indian Boiler Regulation or IBR covers the below-mentioned industrial equipment in steam services:

Boilers along with the feed piping from the feed pump
Full Steam piping
Steam receivers
Heat exchangers
separators
converters
steam traps
evaporators and similar vessels in which steam is generated
accumulators and similar vessels

What is a boiler?

As per IBR, any vessel exceeding 22.5 liters (five gallons) & generating steam is considered a Boiler

Why IBR approval is required?

The primary objectives of the Indian Boiler Regulations are:

Safety: To ensure that boilers and pressure vessels are designed, constructed, and operated in a manner that minimizes risks to life and property.
Efficiency: To promote efficient operation and maintenance practices that enhance the performance and longevity of boilers.
Compliance: To establish clear and enforceable standards that align with international best practices and legal requirements.

If these norms as per the IBR regulation are violated, then legal action may be taken against the concerned by the IBR authorities. In case any accident occurs at the site and then IBR norms are not followed, the matter will be complicated, so it is required that IBR piping is designed, fabricated, erected, & hydro-tested as per the latest IBR code.

Manufacturers and suppliers of boilers and associated components must comply with the Indian Boiler Regulations if those items are used in India. The boiler construction has to be under the supervision of an Inspecting Officer and must be inspected at all stages of construction.

Advantages of IBR Approval

There are various advantages of IBR Boilers as listed below:

As the complete system is manufactured using IBR-approved materials, the Risk of an explosion is minimized.
As approved by IBR, there will not be Legal complications which in turn ensures peace of mind
IBR design and construction compliance ensures longer tube life & lesser breakdown
Finally, Overall Safety Assurance. Indian Government-certified third-party inspection.

Which piping services follow IBR rules?

Services that follow the IBR rules are steam, condensate, & boiler-feed water.

The above services are further classified as follows:

STEAM Piping

1) High-high pressure steam (HHP).
2) High-pressure steam (HP).
3) Medium-pressure steam (MP).
4) Low-pressure steam (LP)

CONDENSATE Piping

5) High-pressures Condensate (HC).
6) Medium pressures Condensate (MC).
7) Low-pressures Condensate (LC).

BOILER FEED WATER Piping

8) High-pressure boiler feed water (HP)
9) Medium-pressure boiler feed water (MP)
10) Low-pressure boiler feed water (LP)

The following conditions should be fulfilled to follow IBR norms.

1) < 3.5-kg/cm2 IBR approval is not required. <10” ID

2) < 3.5-kg/cm2 IBR approval is required. >10” ID

3) > 3.5 kg/cm2 IBR approval is required. <10” ID

Applicable pressure, Temperature, and Hydrotest for the above category of services are as below

Applicable pressure, Temperature, Hydrotest as per IBR Requirements — **Fig. 1: Applicable pressure, Temperature, and Hydrotest as per IBR Requirements**

What is the procedure for Indian Boiler Regulation (IBR) approval?

The procedure of IBR is as under

IBR packages to be prepared
Necessary drawing and inspection fees as per IBR
Drawings are to be sent to the divisional boiler inspector.
Construction can start work on fabrication & erection only when the drawing is in the approval stage.
After drawing approval, respective contractors have to get fabrication permission & welder approval. After taking an introductory letter, the contractor can start work.
After getting approval, the material used for the job has to be offered to the divisional boiler inspector
After completion of work NDT (Non-destructive testing), approval is to be taken from CIB (chief inspector of boiler)
After NDT approval, lines are to be offered for Hydrotest to the divisional boiler inspector
After the hydro test, the job can be considered as work completed.
The design engineering team is responsible for complete approval from the drawing stage still Hydrotest & final closeout of the job.

Documents attached in an IBR package are as mentioned below:

Drawing Index
Pipe data
IBR Design packages general notes.
Pipe wall thickness table.
Pipe wall thickness calculation sheet.
Piping class report.
Pipe Drawings.

The material should be used with an IBR stamp. The material used for IBR are same as per ASTM STD e.g. A106 Gr B or A671Gr CB60 for pipes but the only difference is that the material must come with the following certificate

Form IIIA for pipes.
Form IIIC for fittings.

The above materials must be inspected by the boiler inspector in the vendor shop at that stage & stamped.

As per Indian boiler regulation, all pipes shall be commercially straight and free from longitudinal seaming, grooving, blistering, or other injuries and surface marks. The ends of the pipes shall be cut square. The installed pipes shall be adequately supported.

As the Indian Government has strictly enforced the IBR, all equipment and materials must be imported into India with an accompanied certificate confirming that all imports meet the IBR.

What does IBR service mean?

IBR services mean the inspection, testing, and certifying services that include but are not limited to:

Design review and approval of pipe fittings and valves (Form III-C) in IBR services
Inspection, testing, and certification of pipes (Form III-A) in steam services
Inspection, testing, and certification of materials (Form IV-A)
Witnessing tests required by the Indian Boiler Regulation 1950, or the Code approved by the Central Boilers Board for specific products, for IBR purposes only
Supervision of the Fabrication process and weld quality inspections
Witnessing the welding of the test specimen for the procedure and/or welder certification
Witnessing all nondestructive and destructive tests of welded test pieces in laboratory
Certification of welders qualification and welding procedures
Re-certification of welders (Form XII and XIII)

There are some approved agencies that provide IBR services.

Note that the Indian boiler regulations are periodically updated to reflect technological advancements and changes in industry practices. Recent amendments have focused on enhancing safety measures, incorporating advanced technologies, and aligning with international standards. Keeping abreast of these updates is essential for operators and industry professionals to ensure ongoing compliance.

To sum up, the Indian boiler regulations play a vital role in ensuring the safe and efficient operation of boilers and pressure vessels across various sectors. By adhering to these regulations, industries not only comply with legal requirements but also contribute to a culture of safety and operational excellence. Whether you are a boiler operator, a maintenance professional, or an industry stakeholder, understanding and implementing the IBR is essential for safeguarding lives, protecting assets, and enhancing performance.

Latest IBR Standard

At the time of updating the article, the latest available IBR standard is IBR Amendment 2020, which was published and came into effect in September 2020. The IBR standard and all its amendments can be accessed at https://wbboilers.gov.in/boiler-regulations-1950. So, if you are interested in exploring more about IBR requirements, kindly visit this link.

Differences between IBR and ASME B31.1

The Indian Boiler Regulations (IBR) and ASME B31.1 are both critical standards for boiler and pressure vessel safety, but they serve different purposes and originate from different contexts. Here is a comparative table summarizing the differences between Indian Boiler Regulations (IBR) and ASME B31.1:

Aspect	Indian Boiler Regulations (IBR)	ASME B31.1
Origin	IBR is developed by the Central Boilers Board of India	ASME B31.1 is developed by the American Society of Mechanical Engineers (ASME)
Jurisdiction	IBR is applicable specifically to India	ASME B31.1 is applicable and recognized internationally
Scope	It covers all types of boilers and pressure vessels used in India	ASME B31.1 focuses on power piping systems related to boilers, including design and construction
Focus	Safety, compliance with Indian standards, and certification requirements are the main aims of the IBR standards.	ASME B31.1 provides importance on the design, materials, fabrication, installation, and testing of power piping systems
Design Codes	Includes specific requirements for boiler design and construction materials in alignment with Indian standards	Specifies design, materials, and construction requirements according to ASME standards
Construction Requirements	IBR mandates compliance with Indian codes and certification processes	ASME B31.1 provides detailed guidelines for piping system integrity and safety
Inspection	Requires thorough inspections and certification by authorized Inspecting Authorities in India	Inspection and testing follow ASME guidelines, often involving third-party agencies
Certification	Materials and equipment must be certified to meet IBR standards; certification is required for imports	Certification is handled by accredited bodies adhering to ASME’s quality and safety standards
Application	Enforced by Indian regulatory authorities; applies to equipment used within India	Used internationally but primarily in the U.S. for power piping systems
Enforcement	IBR ensures compliance with Indian safety and operational standards	ASME B31.1 is enforced through industry practices and regulations; often adopted voluntarily
Legal Framework	Part of Indian legislation and regulatory framework	Part of ASME standards, which influence industry practices globally
Documentation Requirements	Requires specific documentation for compliance and import certification	Requires detailed documentation for design, construction, and testing of piping systems

Table 1: Differences between IBR and ASME B31.1: IBR vs ASME B31.1

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