If you work with pressure transmitters, differential pressure gauges, or instrument panels, you have probably heard the term “manifold valve.” But what exactly is it？And why do engineers use them instead of piping together individual valves？
This guide answers those questions in plain language. No engineering degree required.
1. Manifold Valve
A マニホールドバルブ is a block of valves instead of individual valves that are connected by piping. Typical manifold valves are made of stainless steel and are equipped with ニードルバルブ. Depending on the requirements, there are manifolds with 2, 3 または 5 valves.
2. Why Use a Manifold Instead of Individual Valves？
| Benefit | What It Means |
| Fewer leak points | One block has fewer connections than multiple valves |
| Saves space | Fits on crowded instrument panels |
| Faster installation | Mount one block, not a dozen fittings |
| Easier maintenance | All valves in one place, clearly marked |
3. How Does a Manifold Valve Work？
The Manifold Valves are mounted directly to the pressure transmitter or differential pressure transmitter. They are placed between the process pipe and the instrument.
The valves inside the block do specific jobs:
Block valves shut off the process to the instrument.
Bleed (vent) valves are used for venting the pressure trapped on the instrument side.
The equalizing valve is used to equalize high and low side pressure for a differential pressure instrument.
Open and close the required number of valves in the correct order. You can now isolate the instrument for servicing, vent off the trapped pressure or even calibrate the instrument without shutting down the process line.
4. How to Maintain a Manifold Valve
Even manifold valves are designed to last for years and not need any maintenance. From time to time a little problem can occur which can be rectified immediately.
Stop Leakage
Tighten the bonnet bushing slightly to stop the leak. Do not overtighten: excessive tightening increases friction and accelerates wear.
Don’t Leave Manifold Valves Unused for Long Periods
Manifold valves left in one position for long periods can become hard to operate. Schedule periodical partial or full cycle exercising of your manifold valves.
Packing Replacement
PTFE packing rarely needs replacement. If leakage occurs, try tightening bonnet bushing first.
If replacement is needed, safely depressurize the manifold valve before removing the packing nut. Never loosen the packing nut under pressure.
5. Where Are Manifold Valves Used？
| Industry | 応用 |
| 石油とガス | Wellhead control panels, offshore platforms |
| 化学工場 | Pressure transmitters on reactors and distillation columns |
| Power Generation | Boiler instrumentation, steam lines |
| Refineries | High pressure, high temperature, sour gas service |
| Water Treatment | Pump stations, filter monitoring |
6. FAQ
Q1: What is the difference between a 2-valve, 3-valve, and 5-valve manifold？
2-valve: one block valve and one bleed valve for gauge pressure transmitters. 3-valve: two block valves and one equalizer for differential pressure transmitters. 5-valve: same as 3-valve but with two extra bleed valves for calibration ports.
Q2: Which manifold do I need for my transmitter？
Gauge pressure transmitter → 2-valve manifold. Differential pressure transmitter → 3-valve or 5-valve manifold. Need calibration ports？ → 5-valve manifold.
Q3: What is the correct sequence to isolate a transmitter with a 3-valve manifold？
Open the equalizer first, then close both block valves. Closing block valves first can trap high pressure on one side and damage the sensor.
Q4: Can I mount a manifold valve directly to any pressure transmitter？
Most modern pressure transmitters use standard mounting patterns. But not all. Check your transmitter model or send us the dimensions. We will confirm compatibility.
7. Final Thought
A manifold valve connects a number of process instruments in one step. By using it, there is no need to install separate valves for each instrument.
All connections required for a process are mounted on a small manifold which can then be easily serviced for leaks as required.
Need a manifold valve for your project？
We supply stainless steel manifold valves, manufactured from 316 stainless steel. We use PTFE or graphite packing. Full traceability and a Material Test Certificate (MTC) is issued for every batch.
We can recommend the right manifold for your specific application and instruments. Please お問い合わせ with the model of your instrument(s), operating pressure and we will get back to you as soon as possible.
