Should control valves, flow meters, and other instrumentation components be isolated during pipeline pressure testing?

Blowing out requires disassembly; it’s not necessary during pressure testing

It can undergo a pressure test along with the pipeline; this ensures the continuity of the system and also allows for a pressure test of the instrumentation components, thereby verifying their strength :)

One is applying pressure, and the other is testing for leaks. Different.

Pressure testing and leak checking should be carried out together. However, isolation measures should be taken for safety valves, rupture discs, and related instruments. Because the test pressure is generally higher than the set pressure of safety valves and rupture disks.

I agree with what was said on the second floor: it must be removed during cleaning, as there are many debris inside the pipes, which could cause scratches and similar damage to the instruments. However, during pressure testing, it must be tested together with the pipeline fittings to check the overall pressure resistance.

The instrument is not involved to avoid damage.

Remote transmission pressure sensors all have their specified range of operation; whereas for pressure testing of metal pipes, the pressure applied must be 1.5 times the design pressure, and it should not exceed the operating pressure limit of the sensor, otherwise the pressure transducer diaphragm may be damaged

Pressure testing must never be carried out with instruments! The valve is to be handled as appropriate. For hydrotesting, a hydrotest pack is required. Pipelines of the same pressure rating can be tested together when using the same testing medium; pipelines of different pressure ratings cannot be tested together, although it is possible to do so if the pressure difference is very small. Non-through non-check valves can remain in place during pressure testing; for example, gate valves. Non-through and check valves must be removed during pressure testing, such as check valves, otherwise it not only affects the accuracy of the pressure testing but may also cause damage to the valves and instruments. At the removed valves and flow meters, a flanged short section can be used to connect the pipe sections together for unified pressure testing. The instruments must be calibrated before installation, which ensures that they are in good condition; their critical values are generally close to the normal design requirements for pipelines, and some are even lower. Testing them under pressure is likely to damage the instruments.

Instrumentation devices that are installed directly must undergo pressure testing; this is essential. It’s completely different from purging, as during purging the devices have to be removed in any case.

Control valves and flow meters must be removed before the pressure test, as purging is carried out after the test, and dirty water/gas or excessive pressure can damage these instruments.

I agree with the view from the 5th floor. Pressure testing and leak checking should be carried out together. However, safety valves, rupture discs, and related instruments should be isolated. Because the test pressure is generally higher than the set pressure of safety valves and rupture disks.

I agree with the opinion from floor 6! Remove it during purging, and install it during pressure testing!

In my opinion, leak testing is feasible, but pressure testing is not!

Safety valves, rupture discs, and instrument components should be treated on a case-by-case basis: 1. All those that cannot withstand the test pressure must be isolated. Generally, as long as a device can be connected to the pipeline, its pressure resistance will be sufficient to handle the test pressure; however, it is not recommended to include such devices in the testing system, as this would equate to subjecting them to a pressure resistance test as well, and there are specific requirements for conducting pressure resistance tests on devices. The safety valves, rupture discs, and instrumentation components on the pipeline must be removed. 2. Components that interfere with the testing, such as flow restriction orifice plates, must be isolated. 3. Devices that can withstand the test pressure but for which such pressure might cause the measurement range to exceed limits or reduce accuracy must also be isolated, such as inline instruments. 4. Expansion joints on pipelines require temporary restraining devices.

Leak testing is possible, but pressure testing should not be done to avoid damaging the instruments