A pressure and differential pressure transducer would be incomplete without a manifold valve. A manifold valve’s primary function is to stop or isolate fluid flow in order to isolate process media from pressure instruments. A valve manifold included in a tool allows it to be replaced or calibrated without requiring a shutdown. This post will teach us about the many sorts of manifold valves.
What is a Manifold Valve?
A valve manifold is a hydraulic system component made up of one or more isolation or block valves. A valve manifold is made up of standard valves such as ball, needle, bleed, and vent valves. By separating the fluid flow, a block and bleed system like a manifold valve keeps the upstream fluid from contacting the downstream components.
Types of Manifold Valves
Manifold valves are characterized as follows based on their design layout and number of valves:
- 2-way valve manifolds
- 3-way valve manifolds
- 5-way valve manifolds
2-Way Valve Manifold
A 2-way or 2-valve manifold is made up of a single block that includes an isolation valve and a calibration/vent (bleed) valve. They have screwed intake and outlet ports that can be male or female. The block valve has a blue handle, whereas the bleed valve has a red handle.
They are typically made of 316 stainless steel and have standard PTFE valve packing. 2-way valves come in in-line, L-shaped, and Y-shaped forms.
3-Way Manifold Valve
A three-valve or three-way valve manifold is made up of two block valves and one equalizing valve. Differential pressure transmitters are common applications for 3-way manifold valves. Blue handles are used to identify block valves, while green handles are used to identify equalization valves. The block valves are opened and the equalizing valve is closed during normal operation.
A 3-way manifold valve’s block valves provide instrument isolation. The equalizing valve is installed between the high and low process connections of the pressure instrument, delivering equal pressure on both sides.
Due to the requirement for a test connection, the 3-valve manifold is rarely used in the oil and gas business. Some 3-valve manifolds include a blocked test connection.
5-Way Manifold Valve
A 5-way or 5-valve manifold has two block valves, one equalizing valve, and two vent or test valves. The block valves on the high- and low-pressure sides are designated with blue handles, the equalization valve in a green handle, and the bleeding valves with red handles.
During regular operation, the block valves remain open, but the bleeding and equalizing valves are kept closed. A typical example of using a 5-way manifold valve is a differential pressure transmitter. To test the transmitter’s zero, the block valve and the equalizing valve are closed. To calibrate the transmitter for three or 5-point calibration, the test valve is connected to a pressure generator once the pressure has been equalized.
Characteristics of a Manifold Valve
The typical characteristics of a manifold valve are:
- Anti-rotational thrust brush for pressure-tight sealing, uniform packing compression, and small cold flow channels.
- Bonnet/body washer with on-site bonnet retrofitting with a 100% re-sealing guarantee.
- T bar for ease of operation.
- Dual cap.
- Gland adjuster lock nut.
- Adjust the gland seal to compensate for gland wear.
- Anti-blowout spindle with micro mirror stem finishing for positive gland sealing.
- Gland packing has the least amount of air adjustment and the best sealing effect.
- A shutdown spindle tip that is bubble-tight. It provides the user with leakage-free performance and downstream functional safety.
Manifold Valve Body Type
Manifold valves are available in two basic body styles: horizontal style manifold and vertical style manifold. These styles decide the actual orientation of the manifold valve’s main body.
Mounting of Manifold Valves
Manifold valves can be mounted in two ways.
- Direct mounting
- Indirect mounting or distant mounting
Direct Mounting
The manifold valve is directly mounted to the pressure instruments in the direct mount method.
In general, flange and threaded connectors are utilized in direct-mount valves.
Advantages of Direct Mounting
- Less expensive maintenance and installation
- Fewer leak points
- Integrated valves
- The system is still hard-piped
Indirect mounting or Distant Mounting
Indirect mounting, also known as distant mounting manifold, allows the manifold valve to be installed away from the instruments via threaded connections. To connect a pressure instrument to a manifold, flexible or rigid pipework is typically employed.
Advantages of Indirect Mounting
- Easier maintenance and installation
- The pipe is attached to the transmitter.
- Uses standard instrument manifolds
- Uses tubing and tube fittings
Benefits of Using a Valve Manifold
Valve manifolds are used in a variety of applications, ranging from small mobile devices to vast industrial complexes. The manifold valve gives numerous benefits to the system. Among the anticipated benefits are:
- Pressure and heat loss are reduced due to shorter flow paths.
- Improved energy efficiency.
- Easy installation.
- Reduced installation costs.
- There is a reduction in the number of fluid linkages.
- Because there are fewer connections, oil leaks and maintenance are decreased.
