The Rotary Selector Valve or RSV was developed in the early 1900s for use in irrigation systems. By the late 1940s, the product found favor in the growing oil and gas industry throughout Texas and California. The purpose of the unit was to manifold multiple wells into a single group flow line to feed various containment vessels or production facilities and maintain the ability to test single specific wells or sources on command.
Today the RSV is used widely throughout the oil and gas industry in addition to the chemical, refinery, water treatment, pulp and paper, cementing, food production, and general industry applications.
Rotary Selector Valve (RSV-Fig. 1) Components:
- RSV Actuator
- Heat Shield
- Riser Kit
- Thermal Coil
- Thermal Blanket
- Mounting Brackets
- Lifting Pads
Applications:
A multiport valve can be used for fluid or gas systems
- Multiple-port flow
- Single port testing
- Manual or automated operation
- Water injection
- Collection at the tank battery
- Other-market application
The RSV supports the capability of diverting multiple inlet ports, allowing each port to flow uninterrupted into a single chamber known as the body of the valve and out through a single group outlet port. A rotor stem, positioned in the center of the bowl, allows for the selection of a single inlet source to be diverted through a 1.2D or 1.5D flow line elbow and out through a single test outlet port.
The valve position is controlled by manual or automatic operation. Manual operation requires placing an indexing wrench directly on the outer stem of the rotor and rotating to the selected stopping position. The automatic operation uses a hydraulic, pneumatic, or electrical controller that attaches directly to the outer stem of the rotor allowing for local or remote positioning of the rotor to a selected port.
Operation:
The RSV can be operated in a clockwise or counterclockwise direction.
As the rotor passes each port a spring-loaded wiper is engaged against the valve body to seal the seating surface. This creates a self-cleaning action and removes accumulated debris that might restrict proper operation. It also increases the life of the port seal and valve body.
An adjustable, spring-loaded Carbon Teflon Port Seal serves as a soft seal that prevents leakage at the test line and valve body junction. Back-up rings located on the port seal are designed to accommodate excess pressure, higher temperatures, or chemical presence.
- Bidirectional Rotation
- Self Cleaning
- Self Sealing
- Adjustable Sealing Surface
- Back-Up Rings Improve Performance Life
- Improved and Revised Metallurgy for Longer Life and Advanced Product Performance
- Improved Elastomers and Seat Design to Meet Today’s Rugged Standards and Applications
Port Selection and Flow:
The Port Seal can be adjusted with a specially designed tool. The tool has two retractable spring-loaded pins that engage and disengaged via a pistol grip trigger. Each pin fits into a slot located on either side of the adjusting nut.
Specially designed O-Rings prevent external leakage through the valve body or head.
Emergency shutdown facilities; shut down upstream inlet ports in a single or group.
The downstream control valve can be remotely and automatically connected to the upstream setting point based on user requirements. The control system can be operated locally or remotely.
Optional quick disconnect fittings at all inlet/outlet flanges allow simple removal or relocation of the skid.
Special coatings for offshore or extreme conditions.
DESIGN CRITERIA:
- ASME B16.34 (American Society of Mechanical Engineers)
- ASME Sec. VIII, Div. 1 / Div. 2 (FCI- Fluid Control Institute)
- ASME B16.5 (FCC-Fluid Catalytic Cracking)
- NACE MR 0175 / ISO 15156 (National Association of Corrosion Engineers)
- API 598 (American Petroleum Institute)
- ANSI/FCI 70-2-2006 (American National Standards Institute)
- MSS SP-55 (Manufacturers Standardization Society)
- FEA Analysis, Proper Safety Factors, Industry/Local Required Codes
- ASME VIII Division 1 Design Criteria
ANSYS finite element analysis software is employed for the main components of the RSV. Working and test conditions are analyzed and utilization factors (safety factors) to code allowable are verified.
A standard approach is to utilize the ASME VIII Division 1 design criteria and always employ the casting quality factor unless the design is unique, limited in quantity, and customized for specific applications.
Improvements to the RSV continue as the needs of the client base require with respect to metallurgy, flow, line-pigging characteristics, valve size, pressure classes, seals, differentials, controllers, communication protocols, and serviceability, metering capabilities, spill prevention or containment.
Additionally, we are faced with the task of ensuring each design supports ergonomic operation, safety, simplified integration, and environmental protection from leakages, such as H²S fluids or gas.
Simplified Design – 3 Main Parts:
Skid Design:
Based on the results of the analysis conducted using FEA, the Sled meets the requirements of AISC with a safety factor greater than 1.5 for all loading conditions and a safety factor greater than 3 for the Lifting Eyes.
The multiport modular skid system utilizes a simple, design that saves time, money, and human resources. The system accommodates quick connect expandability for future field growth or quick disconnect to move those resources to other areas for improved utilization.
New Designs Based On Customer Requirements:
- ANSI CL 1500 – 2500
- SAG-D – Extreme Temperature
- Full Body Alloy
- Custom Skid – GA/Design
RSV SKIDS WITH A SINGLE FLOW METER:
MULTIPHASE FLOW METER:
The permanent multiphase flow meter (MPFM) uses technology for continuous flow rate measurements. The Typical Multi-Phase Flow Meter operates equally well in both oil and dry gas environments, making it possible to monitor and test dry gas, condensate, and oil wells with a single meter.
Via a remote data link to the multiphase meter, users can validate well data, perform quality control, generate well test reports, analyze well data, diagnose production, and interpret reservoir intervals. By eliminating the need for separators and their associated support systems or controls, the system is ideal for both Onshore and Offshore Applications, satellite, or unmanned locations, including subsea installations.
Since the need for a separator has been eliminated, the requirements for space, load, and maintenance are reduced. Continuous, highly accurate flow rate measurements allow for quicker response time to production anomalies. The typical MPFM has limited or no moving parts and is essentially maintenance-free. Remote monitoring increases the safety of field personnel and allows for better utilization of human resources.
Flow Characteristics:
- The RSV can be operated in a clockwise or counterclockwise direction.
- As the rotor passes each port a spring-loaded wiper is engaged against the valve body to seal the seating surface. This creates a self-cleaning action and removes accumulated debris that might restrict proper operation. It also increases the life of the port seal and valve body.
- An adjustable, spring-loaded Carbon Teflon Port Seal serves as a soft seal that prevents leakage at the test line and valve body junction. Back-up rings located on the port seal are designed to accommodate excess pressure, higher temperatures, or chemical presence.
CONCLUSION:
The RSV Multiport Skid provides a simple, cost-effective solution to manifold fluids in low maintenance, environmentally friendly package. The compact design reduces capital costs and allows for better utilization of resources when and where they are needed. The latest data communication technologies provide continuous feedback to help maintain a high level of operational efficiency and ensure quicker response time to production anomalies.
