Which PRV can keep outlet pressure stable?

If users want to keep a stable outlet pressure for the pressure reducing valve in steam pipelines, those PRV which can reduce Static Pressure should be used.

Both DP17 Pilot Diaphragm Type PRV and Y43H Pilot Piston Type PRV can be used for Steam, but Y43H can only reduce Dynamic Pressure while DP17 can reduce both Dynamic pressure and Static Pressure.

 

1. DP17 is Pilot Diaphragm Type Pressure Reducing Valve, while Y43H is Pilot Piston Type Pressure Reducing Valve.

 

2. Both DP17 & Y43H can be used for Steam Pipelines.  Working Performance of DP17 PRV is better and stable than that of Y43H PRV, but the price of DP17 PRV is higher than the price of Y43H PRV.

 

3. Generally Y43H Pilot Piston Type PRV can only reduce Dynamic Pressure. if the valves installed after the PRV stop working and there's no steam consumption in that pipelines, the outlet pressure might increase, if all the valves work continuously and the steam flow continuously, the outlet pressure can be stable at a setting value. But if the outlet PRV cannot be set, the inside Piston might be stuck or the adjusting spring might be broken.

 

4. For Y43H Pilot Piston Type PRV, if the working temperature is higher than 300 Deg C, Heat Treatment should be done for the Trim material. The pilot Valve spring, main valve sping and adjusting spring should also be changed into Inconel X-750 Spring which can resist high temp. The high temp spring for PRV is not 50CRVA, it should be Inconel X-750. But generally pilot valve spring and main valve spring don't be supplied as spare parts. 

 

5. For DP17 Pilot Diaphragm Type PRV, it can not only reduce Dynamic Pressure, but can also reduce the Static Pressure. That's to say, if valves after the PRV stop working and no steam flowing, the outlet pressure can remain at the setting pressure and won't increase. But clients should specify it clearly in their order if they required to reduce the static pressure ( or said to keep the outlet pressure at a certain setting value) as we need to change the sealing type. Or else, we will offer normal type which often used to reduce Dynamic pressure.