Plant Layout Design Rules | Piping Layout Rules

Written by Anup Kumar Dey in Piping Design Basics

Plant layout design means efficiently placing equipment, piping, instrumentation, and other manufacturing supports and facilities with proper planning during the design stage to create the most effective plant layout. It is directly related to project costs as well. The most efficient plant layout has less overall project cost and the most utilization of all resources.

The main objective of efficient plant layout design is to design and construct the plant in an economic fashion that meets all the process requirements and client specifications while operating in a safe reliable manner. This article provides the basic considerations for the development of plant layout. For more details on any of the listed points, you can refer to any standard piping books.

Principles of Plant Layout

While developing plant layouts following 10 principles are kept in mind.

Plant Layout Principles — **PRINCIPLES OF PLANT LAYOUT**

What is Plot Plan & its requirement?

The plot plan is the master plan locating each unit/facility within the plot boundary for a process industry such as

Refinery
Chemical /Agro Chemical / Petro Chemical / Organic Chemical / Inorganic Chemical
Fertilizer
Pharmaceutical
Metallurgical
Power Generation

It is used to locate the unit/facility.

The following main aspects shall be considered during the development of the layout.

Process requirement
The economy of piping material and cables
Erection & Construction requirements
Safety requirements.
Operation and Maintenance requirements.
Grouping of similar equipment for the convenience of maintenance & safety wherever possible.

Data to be collected before starting the process of plant layout development

Data from the Civil Department

Plane table survey map.
Contour survey map.
Soil bearing capacity.
Nature of Soil
Rail/Road Access.

Data required from Electrical Team

Location of Electric Supply Point.
Supply voltage levels.
Fault Levels.
Voltage Levels required within the unit.
Proposed distribution scheme.

Non-Plant Facilities

Administrative Block
Canteen
Workshop
R&D, QC Lab, and Pilot Plant
GateHouse/Time office
Security Arrangements
Vehicle Parking
Medical Centre
Ware House
Covered Area
Open Area
Solid Warehouse
Liquid Warehouse
Steel / Scrap Yard
Fire Station
Weigh Bridge
Staff Colony

Meteorological Data

Minimum, Maximum, and Normal Temperature during the year
Rainfall
Intensity and Direction of the wind (wind rose)
Seismic zone
Wet and Dry Bulb temperatures
Relative humidity
Flood level

Process Data

Size/Capacity of the processing unit
Knowledge of the type of plant
The sequence of process flow
Hazardous nature of the plant
The Overall operating philosophy
Fully Automatic
Partially Automatic
Manual
Batch/Continuous
Raw material receipt and product dispatch philosophy
Storage Philosophy
Effluent plant capacity and discharge points, incineration requirements, etc.
Type of Hazard
No of flares

Data on Utilities

Source and/or supply point of raw water
Quality of Water available
Water Consumption for the process
The requirement of different types of utilities such as Steam, Air, Nitrogen, DM water, Firewater, Brine, etc.
Capacities and Grouping philosophy.

Statutory Requirements and process plant layout

State Industrial Development Corporation (SIDC)
Central / State Environmental Pollution Control Boards (PCBs)
Factory Inspectorate
State Electricity Boards (SEB)
Chief Controller of Explosives (CCOE)
Static and Mobile Pressure Vessel Rules (SMPV)
Tariff Advisory Committee (TAC)
National Fire Protection Association (NFPA)
Aviation Laws
Chief Inspector of Boilers (CIB)
Oil Industry Safety Directorate (OISD)
Food and Drug Administration (FDA)
Ministry of Environment and Forest (MoEF)

Expansion Philosophy during plant layout development

Within the unit
Additional Units
Near future expansion
Far future expansion

Considerations during plant layout

Normally Construction is permitted on a maximum of 50% of the plot area with a total built-up area equal to the area of the plot (i.e. F.S.I. = 1 (Depending upon the regulation governing the area and the type of industry))
The area reserved for tree plantation shall be 1/3 of the area occupied.
Water storage capacity – 24 hr. minimum.
Domestic water – 100 liters per person per day
Water requirement for Boiler – Steam rating x Working factor
Cooling tower – 11/4 % of capacity as drift and blowdown losses
Washing – 10-15 liters per day per sq. ft. of the floor area of the plant
Gardening – 5 liters per day per sq. ft. of garden area
Parking space – 10% of the plot area

Roads & Paving considerations in Plant Layout

Roads in the plant shall be planned for the effective movement of trucks, cranes & emergency vehicles, etc. Road width (Blacktop) shall be generally as follows unless specially requested.
Main plant road & roads connecting to Plant boundaries, roads for fire fighting access are 6 meters wide (Min)
Secondary roads 4 meters wide (Min)
The turning radius of the road shall be adequate for the mobile equipment & shall clear of any obstruction. The minimum turning radius is to be the same as the length of the vehicle.
The finish of the road i.e. graded or blacktop shall be decided in the beginning while developing a plot layout.
Paving should be provided around the equipment where spillage is likely to occur. For example Pumps or machinery, below furnaces or fired heaters, compressors, etc.
Also paving should be provided below the Air fin cooler those are located at grade.
Area handling acids, alkalis, or toxic material shall be paved and bunded. Proper surface treatment shall be provided for paving to meet the service requirements.

The below sketch (Fig. 1) shows the minimum distance required between the road and the facility. This distance shall be reviewed on a case-to-case basis for the project.

Elevations Requirement

Below data for the elevations should be generally followed.
Underside the base plate of Structural steel: Min150 mm. above HP of finished grade/paving.
Stair or ladder pads: Minimum 75 mm. above HP of finished grade/paving.
Top of Pedestal of Vessel & Tower: Min300 mm. above HP of finished grade/paving.
Top of Pump pedestal: Minimum 200 mm. above HP of finished grade/paving.

Insulation & Fire Proofing considerations in plant layout

Fireproofing requirements for pipe racks, vessel supports, and process structure should be considered as these reduce the clearances with access, pipework, instrument & electrical equipment.
Proper insulation thickness should be considered for pipework & equipment clearances.

Equipment Layout and locations

Pumps: Locate pumps close to the suction source considering NPSH requirements. Pumps & driver axis should be located perpendicular to the pipe rack or other equipment to minimize fire exposure in case of pump seal failure.
Gas compressor or Expanders: Gas compressors should be located downwind of the fired heaters, flare, or any open flame equipment. They may be grouped together for maintenance & operations (Common EOT / drop-down area, the single sunshade can be made)
Plant Air & Instrument air compressors: Plant air & instrument air is vital to the service of the plant. These units should be located near the control room & shall be kept in a safe area sufficiently away from the HAC of equipment.
Heat Exchangers: Heat exchangers are generally placed on grade unless otherwise due to process or technical reasons. (Platform for vertical heat exchangers, Tube bundle removal area, access to mobile crane or monorail with hoist shall be considered)
Air cooler: The air cooler is located in such a way as to allow access to mobile lifting equipment. Preferably air cooler is located in the main equipment row in accordance with process requirements.
Cooling Towers: Cooling towers shall be located away from the process equipment & downwind of the process equipment, substation, and main pipe rack.
Offsite Tanks: Storage tanks (Grouped and shall be surrounded by a dike wall, Primary/secondary roads for adequate firefighting accessibility, Lower elevations than the other occupancies and downwind flares, furnace heaters). Emergency shutdown valve, pumps, manifold & transfer piping shall be outside the dike area.

Considerations for Pipe ways / Pipe racks

Pipe ways or pipe racks should be overhead in-process main unit and at grade in off-site.
Width is determined based on present need + 10% at outset of the job + 15% for future requirements or as specified by the client.
The requirement of expansion bays, anchor bays & bracing shall be checked with the stress / structural engineer at the beginning of the pipe rack layout.

Relief valve and Flare systems

A closed relief valve system
Self-draining
No pocket to avoid condensation & backpressure.
Flare shall be located upwind process unit & storage.

Clearance at Pig Receiver

The area at the end closure of the Receiver shall be kept free to avoid any incident.
Provide a concrete wall a minimum of 20 meters away (Fig. 2) from the end closure if the area needs to be utilized for any equipment.

Personal protection Considerations

Eyewash and emergency showers shall be provided in an area where operators are subject to hazardous sprays or spills.
Breathing air stations in the facilities handling extremely toxic gases/fluids.

Fig. 3 shows a typical plant layout.

What is a Hazard Classification?

Hazardous area classification is the risk locating plan for each unit/facility within the plot boundary for the process industry.
The Plot plan will be used by indicating the boundaries of the risk area.
HAC drawings are generally used by operators while issuing work permits.

HAC Standard

HAZARDOUS AREA: An area in which an explosive gas atmosphere is present, or maybe expected to be present, in quantities such as to require special precautions for the construction, installation, and use of apparatus.
NON-HAZARDOUS AREA: An area in which an explosive gas atmosphere is not expected to be present, in quantities such as to require special precautions for the construction, installation, and use of apparatus.

Process Requirements

Proper interconnection between equipment to achieve intended process parameters.
Normally equipment is arranged in the process fluid flow sequence. Requirement like gravity flow (Equipment Drain piping), Thermosyphon system should be considered, and Limitation of pressure & temperature (process parameters) to be considered
The requirement of upstream and downstream pipe lengths for instruments.
Hazardous & Toxic fluids shall be identified. (H₂S, Cyanide, Methanol, etc.)
Equipment handling hazardous fluids like flares and direct-fired equipment containing open flame shall be located separately.
Similarly, equipment handling toxic material shall be located with restricted access or in accordance with local statutory regulations.

Economic Considerations

Equipment shall be located without affecting the process requirement for maximum economy of pipework & supporting steel with consistent standard clearances, construction, and maintenance & safety requirements.
Runs of exotic material & large bore piping shall be minimized.
Optimum utilization of the structure to be ensured.

Erection & Construction

Road access for the erection of pipe support/pipes and equipment.
The clear area for the crane to erect equipment on the location from the trucks.
The minimum one side of the pipe rack shall be kept clear.

Fig. 4 shows relative locations for area Layout.

Water Hammer Basics in Pumps for Beginners

Written by Anup Kumar Dey in Mechanical,Process

Water Hammer Basics

Water hammer, Pressure Surge, or hydraulic shock, is a term for the destructive pressure increase and accompanying shock wave that takes place in pipeline or piping systems when the flow rate of liquid changes suddenly. A large vapor pocket is formed because of this within the pipeline; and when this vapor pocket collapses, a highly powerful, bidirectional pressure wave propagates away from the origin at a very very high speed. In extreme situations, the magnitude of this shock wave can reach up to 100 times the closure velocity of the pocket. In the actual scenario, This huge force can force the pump shell to rupture.

What Can Cause Water Hammer?

Sudden flow restriction due to valve closure or pump trip, load shedding, etc. is the most popular reason behind water hammer phenomena. If any of the above is the actual cause, the pump operators can easily reduce or even eliminate the possibility of water hammering by using proper valve closure procedures.

However, the pumping environment can also be one of the reasons for its creation. For example, In the phosphate industry pressure surge in pit pump applications are the most common. In such cases, during operation, the suction pipe can become blocked, but not during valve closure. While quick filling of long pipelines Surge can occur where the flowing fluid and the static fluid meet.

**Destructive Impacts due to Water Hammer**

Predicting Water Hammer

Since a water hammer or surge manifests as a shock wave, it is really very difficult to predict its point of origin or source until a rupture arises. Anyone or anything in close proximity to these pipelines is at high risk in the event of a water hammer and the resulting pipeline movement, so pump operators have to be extra cautious when there is any chance of a water hammer.

Water hammers may not be so destructive in all situations. In less severe cases, a banging or hammering noise is heard and it may also bend or move the pipe or its support.

Difference between Water Hammer and Cavitation

Sometimes, a water hammer or surge is confused with pump cavitation, but both are two different phenomena. However, cavitation can easily increase the potential risk of water hammer. In normal practice, cavitation itself is not always so destructive. The main difference between the two is that Cavitation involves the implosion of many small, localized vapor pockets whereas the water hammer involves the collapse of a single large vapor pocket. Cavitation damage builds up over time before causing a part to fail; conversely, a single instance of water hammer may cause catastrophic damage.

Extreme cavitation can occasionally result in a water hammer. For example, when cavitation is not severe enough to stop operation entirely but severe enough to impede pumping, a vapor pocket is expected to form in the pipeline. When pumping resumes, the pocket collapses, thereby causing a water hammer.

How to Stop Water Hammer

The main step towards reducing the water hammer possibility is by educating the pump and valve operators or plant operators.

As it is well-known that quick valve closing is the ultimate cause of water hammer generation, it is the responsibility of the valve operators to close the valves in the correct way as mentioned in the operating manuals.

For situations where the pump suction gets blocked, plant operators must stop the pumps following the same sequence of steps that they would use while a controlled shutdown is planned. In such cases, the vapor pocket will close at the minimum possible velocity this, in turn, will limit the magnitude of the shock wave to a minimum.

Operators should attempt to control the suction pipe movement and position it at the pipe entrance to keep it free from blocking. However, if there is a slump in the mining or dredging face, the pipe may still become blocked. Such risks can be carefully considered before moving the suction pipe entrance, as it may cause a water hammer.

So, by identifying and understanding the causes of surge or water hammer in pumps, and by following proper operating procedures, operating manuals, and vendor guidance notes, plant operators can prevent a disaster from happening due to water hammer. However, the pumping environment also plays an important role and situations may require expert help.

Some more ready references for you…

Introduction to Pressure Surge Analysis
Understanding Centrifugal Compressor Surge and Control
Pipe Stress Analysis from Water Hammer Loads

References

https://campaign.ksb.com/blog/what-causes-water-hammer

Check List for Reviewing of Shell & Tube Heat Exchanger Drawings

Written by Anup Kumar Dey in Mechanical

This article will highlight a few of the points that are required to be checked while reviewing the Shell & Tube Heat exchanger. The list is not exhaustive but provides a simple guideline for beginners.

Basic Checks for Shell & Tube Heat Exchanger

Check the Pressure Design Code to be applied and Applicable local regulations to be applied.
Check completeness and correctness of the information, dimension, impingement plate, gasket recommendation, the applicability of IBR, TEMA type and configuration, etc. are available on the datasheet.
Maximum design temperature and minimum design metal temperature
Ensure the latest issue of the process data sheet is followed.
Check if any specific notes to be highlighted like anodic protection or sloping shell, any special service requirements like NACE/Sour service, etc. are applicable which puts restrictions on material requirements.
Ensure adequacy of shell Internal Diameter to accommodate all tubes with given pitch and orientation, the required number of tie rods, considering the provision of impingement plate, minimum U tube radius, and groove width, ligament as per TEMA recommendation is checked before starting design work.
Design codes including wind, seismic load, and any reference books with edition number and year of publication and amendments if any have been specified and used in the calculations.
Applicable standard specifications, Job specifications, and standards with their revision numbers.
Nozzle schedule indicating the size, rating, and nozzle neck thickness, projections and surface finish of gasket surface of nozzle flange (projection to suit insulation thickness and facing to suit gasket material), Nozzle location, Orientation, etc.
Test pressure including any temperature correction
The drawing block, drawing number, and distribution are in line with the project procedure.
Reference drawing numbers of standard drawings are indicated if details are not given on the drawing.
The reference datasheet number with the latest revision is indicated in the drawing.

Shell and Tube Heat Exchanger — **Figure Showing Typical Shell & Tube Heat Exchangers**

Provision of Instrument connection as per TEMA and Provision of vent or drain connection for testing
Support details (lugs, saddles) indicating size, numbers & PCD of foundation bolts. Foundation bolts are to be specified with their size and thread pitch in mm.
Typical applicable weld details of plates, Nozzles, and other attachments depending upon the material of construction, and the thickness of parts. (Special attention required. for cladding/lining)
Provision of standard attachments like Nameplate, Earthing boss,
Tube expansion requirements for strength welded tubes.

Adequacy and applicability of general notes

Ensure that the statement “In general the provisions of ASME / TEMA have to be followed in addition to the local company specification.”
On-site storage is required for more than 12 months prior to installation.
Surface preparation and painting, the surface finish of flange faces with respect to specified gaskets to be specifically checked
In the case of the stacked heat exchanger, a note stating that the final hydro-test shall be conducted in a stacked condition must be added.
Surface preparation and protection requirements
For stacked heat exchangers, the requirement of shim plates as required for adjustment shall be included.
Sliding support anchor bolts should be hand tightened and for high-temperature exchanger Teflon / graphite/Stainless steel sheet below sliding saddle to be indicated with the responsibility of its provision by the supplier.
Grooving requirements for shell side clad tube sheets.
In the case of the cryogenic exchanger, wooden saddles/Foam glass of adequate thickness below saddle plates are to be indicated.

Check if the test ring is included for ‘U’ tubes kettle type & floating heat exchangers. The testing arrangement as required for other types has also been included in the supplier’s scope.
Chemical cleaning connections requirements, Thermowell connection requirements, Pressure gauge connection requirements
Check if lifting lugs, jack screws, and locating pins are provided.

In the case of ‘U’ tubes

The smallest radius of the tube bend not to be less than 1.5 times the O.D. of the tube
Check the requirement of Heat Treatment for the inner two rows for C.S. tubes bend
Check the requirement of solution annealing of S.S. tube bends
For large diameter, bundles check for U-tube rear support requirements.

Check the tube-to-tube-sheet joint critically with respect to joint requirements as per ASME Sec. VIII div-1 appendix ‘A’ provisions.
Check details for Tie rods, spacers, runner bars, sliding strips, and sealing strips (if applicable are indicated)
Check vent/drain notches are provided on baffles in the Horizontal Heat exchanger.
Check if pulling/lifting arrangement is provided for removable tube bundles and clear space required for pulling bundle is shown in dotted in the schematic.
Check vent/drain holes are provided at the highest & lowest points on pass partition plates.
If an expansion bellow is required, proper details are included for design by a specialist vendor including the applicable design codes.
For vertical heat exchangers which require expansion bellows, a note near the expansion bellow sketch must indicate the minimum civil cut-out size required to clear the tie-rod lugs (For this purpose assume that the bellows design by the vendor will have the tie-rod provision)
Check section lines are appropriate for materials of construction.

Check about Hold List

Instrument Nozzles
Orientation of nozzles
The orientation of attachment like a) Lifting lugs b) Nameplate, Earthing boss
Orientation foundation bolts / support lugs / saddle & Position of fixed & sliding support

Check completion and correctness of Nozzle Orientation
Specific requirements of relative locations are maintained as per process datasheet
If some special gasket or its equivalent has been specified, fix the criteria of equivalence in the job specification.
Post weld heat treatment required for process reasons or for weld overlaid bonnet or channel
Ensure that nozzle orientation also indicates the expansion bellows tie-rod lugs orientation
Ensure that squad-check comments are incorporated
Ensure that drawing is in line with P & ID and equipment modeling.
The number of cycles to be considered for the bellows expansion joint design.
Fatigue analysis is required for flanged and flued expansion joints, and the number of cycles is to be considered.
Additional requirements for low chrome steels in high temp. or high-pressure hydrogen service.
Materials of construction.
Weight (empty, full of water and operating)
Painting requirement.

Few more Resources for you..

Various Articles related to Heat Exchangers
Articles Related to Pumps
Piping Design and Layout
Piping Stress Analysis
Piping Materials

Connection Procedure (Alignment) of Process Piping with Rotating Equipment

Written by Anup Kumar Dey in Construction,Maintenance,Mechanical

This article provides the necessary brief information to assist the site engineers/field engineers/ construction engineers during the first installation and connection of piping with the relevant rotating machinery.

Preservation

During operations, the equipment should be preserved and protected in compliance with the supplier’s procedure. In order to prevent any grit and foreign matters from entering, make sure that all paths and openings are properly blocked up and sealed. Antidust covers should remain installed until the final alignment is completed.

Alignment

Once the skid or module has been leveled and grouted, the machines should be aligned according to specification, after this operation, they will be available for piping installation (including instrumentation and electrical connection piping).

Machine leg anchor bolts should be tightened and the relevant washer (Belleville washer) should be locked in order to anchor the machine to the skid. The axial and transversal keys should be fixed in position, but no fixing welding, or pinning shall be carried out.

Piping

Electrical Insulation

Do not perform any welding operations on pipes connected to the foundation, machinery base plates, or the machinery itself, without the proper direct grounding connection with the welding transformer. In order to avoid any damage to the machinery supports caused by dispersing current, grounding cables should not be connected to any part of the rotating machinery (base plate, pedestal, control circuit apparatus, etc.).

Temporary Supports

During piping construction, pipes can be temporarily connected to the machine. Pipes should be properly supported (with temporary supports) in order to avoid stress or interactions during the alignment operations. While those activities are carried out the machine must be firmly locked in position.

Piping Completeness

Before connecting pipes to the machine and checking the final alignment, all operations on piping systems have to be completed. Including the following activities: pressure tests, washing, air flushing, and permanent support installation (fixed, sliding, and elastic supports). While those operations are carried out, piping has to remain always disconnected and insulated from the machine.

Permanent Supports

Pipes have to be connected to permanent supports in order to be installed in the correct final position so that elastic supports are pre-loaded at the required load (cold position) with assembled pins.

Pipes should be sustained by supports so that connection flanges are within the coupling tolerances.

If the customer is in charge of the piping supply, he has to provide all the relevant information.

Flange fitting tolerances between machine and piping

Parallelism

Before fixing the piping flanges on the machine flanges, planes have to be aligned in parallel as shown in Figure 1.

The difference between the maximum and the minimum distance will be a “T” misalignment value, to be checked with the acceptance criteria sheet (see Figure 1). After each adjustment, please check and record the measurements until an acceptable alignment is reached.

**Fig. 1: Flange Alignment Acceptance Criteria**

Clearance

Check the gasket type, material, and dimension. The distance between flanges should be just enough to insert the gasket by sliding it inside without causing any damage to it and the flange planes.

Concentricity

Check the dimensions of flange hold down bolts and align the relevant holes. Flange bolt holes have to be aligned within a maximum 3 mm offset, and in any case, when flanges are coupled, hold-down bolts should freely slide without any interference through holes.

Piping connections

Preliminary Tests:

Make a visual inspection of the coupled flanges. Surfaces should generally be in good condition; in particular, scratches in radial direction and oxidation are not admitted. As regards flange condition acceptance criteria and detailed prescriptions, please refer to ASME B16.47 and B16.5 procedures.

Connection Sequence

Pipes should not be firmly connected to the machine until final piping supports are installed. In order to avoid any undue stress, piping installation should never start by the machine flange side.

Elastic Support Check

Once the machine flange and piping flange tolerances have been checked, release the elastic supports by removing the locking pins, and make sure pipes remain in position (free to spring around the fixed position).

Connection References

While piping machine tightening activities are carried out, install dial gages on the machine legs in order to monitor any abrupt displacement and the alignment equipment too.

Pre-Tightening Operations:

Starting from one of the pipes to be connected, tighten the four tie rods (staggered tightening) between the machine flange and the relevant piping flange, until an intermediate torque is reached (70%-80% of the torque value indicated in the specification).

Remark: All operations executed until now have to be performed with the machine fixed on the base plate, in order to keep the required position according to the alignment specification.

Intermediate Alignment Check

Release the machine, by unscrewing the fixing screws of the machine axial keys, and by releasing washers (or Belleville washers). Check for any dial gauge range. Verify that the alignment has not changed.

– In case of small alignment variations, some adjustments are admitted only on the horizontal plane. If during the alignment correction, some elastic responses (spring effect) are sensed by the dial gages, it will not be possible to proceed with the final tightening, and piping restoration will be necessary.

– In case of considerable alignment variations it will not be possible to proceed with the final tightening, and piping restoration will be necessary.

Piping Restoration

Piping restoration operations shall consist in displacing pipes by acting on their supports, in order to eliminate forced assembling with the machine (cause of misalignment). If this operation is enough, cutting and welding of the piping will be necessary in order to correct its geometry.

Perform the same Pre-Tightening operations and checks, verify the Intermediate Alignment restoration for all remaining pipes to be connected, make sure the machine is always fixed on the skid during pre-tightening, and do release it before performing the alignment check.

Final Tightening

After reaching the pre-tightened piping condition (70%-80%) and machine-aligned condition, fix again the machine on the skid (by tightening the axial keys and the washers or Belleville washers). Proceed by tightening rods at the final torque values.

Alignment Check

After the final tightening, release the machine; verify the alignment and the DBSE between the machines you are working on and the adjacent machines.

Final Fixing

With the aligned machine and all pipes tightened at the required torque values, proceed with the final arrangement by fixing the machine and/to the skid, as follows:

– Fix the axial keys, with the required fixing screws, and furthermore (if possible /if foreseen) with welding points.
– Fix in the required position machine legs to the base plate (or to the proper supports on the base plate) by using the required pins.
– If calibrated washes are provided, make corrections in order to obtain the required clearance.

Final Alignment Check:

After the final tightening, please verify the Alignment.

Few more Useful Resources for you..

Shaft Alignment Methodology for Compressor and Driver
Connection procedure (Alignment) of Process Piping with Rotating Equipments: An Article
Alignment Check Methodology in Piping Stress Analysis using Caesar II
Few articles related to Pumps

K-FACTORs (MINOR LOSSES) – HOW WE CALCULATE THEM?

Written by Alex Matveev in Process,Start-Prof

K-factor for incompressible liquid

One of the most typical questions asked by process or hydraulic engineers is what is the value of hydraulic resistance (K-factor) of piping component (fitting, valve, etc) and how to calculate it for different types of flow? This is one of the most fundamental questions we deal with in PASS/HYDRO SYSTEM, and I will be happy to share some knowledge and experience with it. And let’s start from the most simple aspect – K-factor for incompressible liquid.

Few References for K-Factor Calculation

The most often referenced document for minor pressure losses in the piping is Crane Technical Paper 410 (or simply Crane TP-410). Here you can buy the latest version:

https://store.flowoffluids.com/TP410-US.html

However, it is not the best or most comprehensive source of data on K-Factors! Another much more advanced and respectable world standard is the famous “Handbook of Hydraulic Resistance” by Russian Professor I.E. Idelchik. This book became a reference book for generations of piping hydraulic engineers. Please read what Trey Walters, the President of AFT, writes about Professor Idelchik and his book, in his blog: “How a Russian Hydraulics Handbook Gained the Respect of the American Nuclear Industry”.

The latest 4th English edition is available here:
https://www.begellhouse.com/ebook_platform/5877598576b05c67.html

Another worldwide acknowledged and must-have book is “Internal Flow Systems” by famous BHRA researcher D.S. Miller.

This book exists in different editions. We use the 2^nd edition (from BHR Group), and it is still possible to buy it via Amazon or other online book stores. The latest 3rd edition is mentioned here https://www.mentor.com/products/mechanical/flomaster/don-miller/internal-flow-systems , but we failed to order it (for reasons unclear for us).

So PASS/HYDRO SYSTEM basically uses Idelchik K-Factors crossed-checked by Miller data. Moreover, I.E. Idelchik personally checked and tested some correlations for the initial version of PASS/HYDRO SYSTEM 40 years ago!

But this is only the top of the list of K-factor sources.

Another very useful and important source of information is IHS ESDU documents.

The related ESDU series are the following: – ESDU Fluid Mechanics, Internal Flow Series – ESDU Fluid Mechanics, Internal Flow (Aerospace) Series – ESDU Heat Transfer Series. Many interesting reviews and references are hidden there.

There also are some recent reviews – of which I especially like “PIPE FLOW. A Practical and Comprehensive Guide” by D.C. Rennels and H.M.Hudson”.

K-factors for T-Junction

Calculation of K-factors of T-junctions is one of the most complex topics, as their values depend on 1) ratio of run and side branch flow rates 2) ratio of side and run diameters 3) type of T-junctions (different variants of combining and dividing).

K-factor for T-junction — **T-Junction**

This subject was studied for almost a century, and still, there are holes! I will only consider 90-degree tees here and will give the most important references. Besides Idelchik and Miller (which give a good review on this – but not free from errors!) and 2 ESDU documents (ESDU 73022 and ESDU 73023), there are several classical experimental research works which we (and other specialists) use. Below are some most important of them.

First of all, classical articles by A. Gardel:

Gardel A. 1957. Les Pertres de Charge dans les Écoulements au Travers de Branchements en Té. Bull. Tech. De la Suisse Romande 83:123-130, 144-148.
Gardel A., Rechsteiner G.F. 1971. Les Pertres de Charge dans les Branchements en Te des Conduites de Section Circulaire. Publication No. 118, Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland.

Other classical works are articles by Hidesato Ito and his colleagues:

Ito H., Imai K. Energy Losses at 90° Pipe Junctions. Proceedings of ASCE. Journal of Hydraulic Division. Vol. 99, No HY 9, 1973, pp.1353-1368.
Kenji Oka, Takahito Nozaki, Hidesato Ito. Energy Losses Due to a Combination of Flow at Tees. JSME International Journal Series B. Vol. 39, No 3, 1996, pp. 489-498
Kenji Oka, Hidesato Ito. Energy Losses at Tees with Large Area Rations. Transactions of ASME. Journal of Fluid Engineering. Vol. 127, No 1, 2005, pp.110-116

And at the beginning of this century, two students of Dr. Ahmet Selamet from the Ohio State University – Adam Christian and Jacques Paul – and other members of his research team made very good experimental work and filled some “holes” for symmetrical combining and dividing T-junctions:

Christian A.M. The Effect of Interface Geometry on Flow Losses in Right-Angled Tee Junctions. MS Thesis. The Ohio State University. 2003. 113 pp.
Christian, A., Selamet, A., Miazgowicz, K., and Tallio, K., “Flow Losses at Circular T-junctions Representative of Intake Plenum and Primary Runner Interface,” SAE Technical Paper 2004-01-1414, 2004.
Paul J. Effect of Interface Geometry on Dividing and Combining Flow Losses in Right-Angled Tee Junctions. MS Thesis. The Ohio State University. 2005. 158 pp.
Paul, J., Selamet, A., Miazgowicz, K., and Tallio, K., “Combining Flow Losses at Circular T-junctions Representative of Intake Plenum and Primary Runner Interface,” SAE Technical Paper 2007-01-0649, 2007.

Of course, this is only the tip of the iceberg! Minor losses for non-circular pipes, for compressible flow and multiphase flow, are other huge topics. And there are still lots of holes in our knowledge… But more about this and other topics in future articles!

So please join us in our journey for dark and secret places and hidden treasures of piping hydraulics!

Few more Resources for you..
Stress Analysis using PASS/START-PROF
Process Design related articles
Piping Design and Layout

About the Author: Leonid Korelstein (LinkedIn) – VP on R&D of PSRE Co (LinkedIn), and one of the leaders of PASS Suite (LinkedIn, Facebook) team. He is also the Product Manager of PASS/HYDROSYSTEM (LinkedIn group), PASS/RELIEF and PASS/INSULATION software. Leonid has Ph.D. in Mechanics and Mathematics and is Associate Professor (for Chemical Plant design and simulation software) in Mendeleev Chemical University, member of AIChE, active participant of DIERS, EDUG, and TUFFP research communities, co-author of AIChE CCPS GPREH book and Russian GOST 12.2.085-2017 standard for pressure relieve systems sizing. He is also an active member of the ASSESS Initiative.

Long Lead Items for a Process Piping Industry

Written by Anup Kumar Dey in Mechanical,Process,Procurement

After confirmation of funding gates during FEED; major oil & gas firms prepare the novation stage for Long Lead Items (LLI) with the purpose to deliver early beneficial engineering for the selected facilities inherent to every piece of equipment. The identification of LLIs is followed by inquiry requisitions to bidders and then evaluated technically prior to POs and consequent awards to vendors. This article explores the design for pre-fabrication of yard-mounted elements per LLI, a practice considered cost-effective and low risk vs stick-built mounted facilities. The piping engineering task force is a major player in delivering AFD work packages for the Novation of LLIs prior to EPC awards.

What is a Long Lead Item?

Long lead item refers to the equipment, product, or system that is identified at the earliest stage of a project to have a delivery time long enough to affect directly the overall lead time of the project during the EPC phase.

To reduce the schedule impact, procurement activation is pursued as early as necessary. In order to achieve Start-up schedule milestones, some LLIs are procured at an early project time, typically at the back end of the FEED stage.

Due to economics and risk, certain activities in LLIs are envisaged and agreed upon earlier to EPC and designed during a bridging period of beneficial engineering applied to LLIs in order to satisfy demands that emerged from Purchase Orders between the stakeholders. This activity is called “Novation of LLIs”, involving the Oil-Gas producer (Client), FEED Contractor (Buyer), LLI Vendor (Supplier), and EPC contractor (LSTK).

Type of Long Lead Items – Hydrocarbon Processing Industry

Long lead items are determined by Procurement in combination with Engineering and Process management. Delivery times are predominantly the function of manufacturing time (constrained by material, energy, and demand). Below is an LLI list with potential candidates, during the Pre FEED evaluation of a Hydrocracking Unit.

Once the Long lead item lists candidates are approved by Procurement during FEED, Pre ORDER RFQ status is set up to PO Placement for LLI AWARD. Planners adjust a temporary schedule with agreed milestones, normally orbital to TBE, where comments and bidder queries are addressed.

Once LLI is awarded the NOVATION starts. COLUMNS are the most valuable LLI due to CLIPS. For other LLIs, only a PLOT-PLAN dimensional and Stress verification is sufficient to NOVATE.

Delayering LLI Deliverables for a VERTICAL COLUMN

**Fig. 2: Delayering of Vertical Column**

Step 01 – Accessibility: Conventions are agreed upon for access miscellaneous. PIP standards used to be acceptable in absence of well-defined parameters

Step 02 –Internals / Nozzle Orientation: Passes for trays are taken preliminarily from MDS to generate a first design for all Man-holes, Thermowells, and distributors (for accessing/removing internals avoiding downcomers) encompassed with Plot-Plans and 3D Models (if available). Vendor GA to replace MDS (when issued)

Step 03 – Ergonomics: Access to valves, instruments, and each nozzle is agreed upon with Operations.

Step 04 – Large Loads relocation: Large valves, blinds, or any other elements that can be relocated to structures to alleviate clips are discussed and agreed upon.

Step 05 – Level Instruments: Level instruments have a large bearing on the definition of platforming, internals, and nozzle orientation.

Step 06 – Platforming allowable: Maximum spans are agreed upon or waived where necessary.

Step 07 – Nozzle projection: Nozzle projection in excess or defect to calculation per ASME is agreed with the Oil Company engineering rep and Mechanical Engineering.

Step 08 – Utility Risers: Utility Stations and Steam Out, required in columns in centralized headers rising from a dedicated angular area, diverting to each consumption point.

Step 09 – Miscellaneous: Davits, Internal ladders, Skirt Opening & vents, Name Plate, Stiffening Rings, Plate Welding, Earthing and Tailing Lugs, etc., are oriented by Piping (mainly as comments to the Vendor’s GA).

Step 10 – Transportation & Lifting: Lifting Trunnion and Tailing Lugs are oriented by the Construction Engineer. Crane’s standing position is determined by Lifting Studies first.

Step 11 – Pre-Dressing & Erection: Columns can be fully pre-dressed, Partially dressed, or completely undressed prior to Erection.

Step 12 – Fireproofing & Fire protection: Fireproofed surfaces are to be defined as well as pre-action sprinkler rings and dry risers.

Step 13 – Insulation: Insulation has bearing in nozzle projections. Rings and clips to support insulation are fully defined by the LLI vendor.

Step 14 – Tolerances & Welding: Welding procedures and fabrication tolerances are reviewed and commented on by the Piping Material engineer to be in compliance with Client standards and International codes.

Step 15 – Hookups & assemblies: Vents, drains and Instrument hook-ups are not defined at this stage of the project (nor necessary in most cases). Where required, agreement w/Client is to take place.

Step 16 – Piping Classes: In general only Class index, Technical Requirements, and Valve selection guides are only available. Dummy, corporate, PIP, client, or temporary Piping Classes might be needed, for 3D Modelling and to justify certain specific designs or arrangements (particularly branch tables, due to s.i.f affecting stress calculations, might be temporarily determined)

Step 17 – Wall thickness calculation: Usually full flange rating thickness is initially considered for estimation and quantification and re-used by Stress Engineers to Novate. However, where Line List is complete, a second pass using these values might be needed if too conservative for evaluating certain stresses, particularly due to inference in vertical loads.

Step 18 – Nozzle Loads – Piping Stresses: Nozzle loads are the net forces and moments exerted on equipment nozzles, that need to be within allowable limits pre/determined. Pipe stress analysis (thermal flexibility analysis) predicts both stresses in piping and loads on nozzles resulting from thermal gradients/transients, weights, pressure (sustained), and bolt-up strain.

Step 19 – Platform Loads: Nodes from stresses outputs; directly restrained statically or elastically from structural platforms, are to be passed to the Civil Group, including a graphic showing the application point, for Platforming Design and Engineering considerations (for Novation in particular, sizing the Platform Clips).

Step 20 – Standard & Special Piping Supports Nodes from stresses outputs; directly restrained statically or elastically from the Equipment skin, are to be passed to the Civil Group (for beam sizing) and the Mechanical Group, including graphic showing geometries, application point, and Loads, for Vendor’s Engineering considerations (for Novation in particular, sizing the SPS Clips)

LLIs – Novation – Design Review Report & EPC Handover: Finally a 3D Model Review is discussed and agreed upon final changes, and reports are delivered. The Buyer then Handover the Long Lead Item Supply to the awarded LTSK Contractor.

About the Author: The above article has been prepared by Dr. Javier Blasco Alberto, Associate Professor, School of Engineering and Architecture, University of Zaragoza. He also collaborates actively with InIPED. This is reproduced with his permission in this blog as I feel it will be helpful for readers. To know more about the Author Please click here

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