Possible Failure of Pr. Transmitters

Pressure spikes in excess of the transducer's rated Max pressure.

You need very fast diagnostic equipment to measure instantaneous pressure spikes, a gauge will not show them.

It's not uncommon to have very quick and very high pressure spikes in this type of application. Even the fastest relief valves can allow very quick (milliseconds) pressure spikes in the system. Also you may experience pressure intensification on the rod end of the cylinder, which can be far greater than the line pressure on the blind end. This is due to the difference of area, the rod end can be subject to much higher pressure than the blind end when the cylinder is being extended.

These are my best guesses without seeing a schematic of your system.

Hope it helps.

Get a handheld diagnostic tool such as the HMG3000 by Hydac, and spec in properly rated transducers to measure your pressures.

Dear Sir,

Thanks, this point is raising more question about design consideration failure than product failure. As you rightly pointed that there is a very fast pressure cycle.

Thanks Again,

In addition, if the pressure pulsates rapidly, the transducer might be subject to metal fatigue.

In this case how sould I protect my instruments from failing. We used snubbers but due to snubber presence of the rated pressure cycle we got undesired error of approximately 10 - 15 bar and even higher due to the cycle time is in msec.

I think the snubbers are a good idea, but I don't yet understand the 10-15 bar error. It is possible that a hydraulic accumulator shortly after the pump would help to smooth out pressure pulsations (and reduce noise, if that is a factor). Fast-acting valves such as solenoid valves or quarter-turn manual valves might also be issues, but I don't know how much.

It sounds to me that you may need to look more closely at your system as a whole rather than point at the part/s that failed. If you are experiencing pressure spikes, and undesirable things, maybe you need to install an accumulator as suggested, and get a higher response relief valve. A properly designed hydraulic system will not damage any piece of equipment used in it. A poorly designed system can have the ability to wipe out components very quickly. It sounds like you need a highly skilled hydraulic guru to take a look at your system to help you find out why you are experiencing these issues.