Products: VALVEPARK PRR01 pressure reducing regulator, PRR02 pressure relief regulator
Operation: self-acting, no external power required
Controlled pressure: downstream pressure for PRR01, upstream pressure for PRR02
Size and pressure class: 1/2"~10" (15A~250A), ASME Class 150~300 (PN16~40)
If you need to hold the downstream pressure of a pipe at a set value, choose the PRR01 pressure reducing regulator. If you need to keep the upstream pressure from exceeding a set value, choose the PRR02 pressure relief regulator. Both models are self-acting: the valve opens and closes on fluid pressure alone, without external power or compressed air.
A self-acting regulator combines the part that senses pressure, the part that compares it with the set value, and the valve in a single body.
A pressure reducing regulator (pressure reducing valve) lowers the downstream pressure to a preset value and holds it there in piping where the supply pressure is high or fluctuates. In the self-acting type, the downstream pressure pushes on a diaphragm (a thin membrane that receives pressure) while a spring opposes it with the set pressure, and the valve opening is determined at the position where the two forces balance. The set pressure is adjusted by how far the spring is compressed in advance (preload).
Because a self-acting regulator reduces the investment in auxiliary power equipment, it is widely used in the extensive piping networks of gas, water and heat suppliers. PRR01 and PRR02 are regulators for industrial piping. PRR01 has its valve body installed in the pipe at the point where pressure reduction is needed, and the downstream pressure is sent through a connecting line to the control section below the valve. PRR02 is installed in a bypass line connecting the discharge side and suction side of a pump; when the discharge pressure exceeds the set value it opens and returns the fluid to the pump suction side.
The English product names are Pressure Reducing Regulator for PRR01 (a regulator that lowers pressure) and Pressure Relief Regulator for PRR02 (a regulator that releases excess pressure). The numbers 01 and 02 distinguish the two models.
PRR01 for downstream pressure, PRR02 for upstream pressure
| Controlled pressure | Model | Operation |
|---|---|---|
| Hold downstream pressure (pressure reduction) | PRR01 pressure reducing regulator | Closes when downstream pressure rises, opens when it falls |
| Hold upstream pressure (overpressure relief) | PRR02 pressure relief regulator | Opens when upstream pressure exceeds the set value, closes when it falls |
PRR01 pressure reducing regulator
PRR02 pressure relief regulator
PRR01 is a pressure reducing regulator that holds downstream pressure constant, matching the outlet pressure to the set value even when the upstream pressure changes. The valve closes when downstream pressure rises and opens when it falls.
PRR02 is a pressure relief regulator that holds upstream pressure at the set value. When upstream pressure exceeds the set value the valve opens and releases the excess pressure, and when the pressure drops it closes, preventing overpressure damage to the piping.
| Item | PRR01 and PRR02 (common) |
|---|---|
| Size | 1/2"~10" (15A~250A) |
| Connection | Flange, butt weld (BW), socket weld (SW) |
| Pressure class | ASME Class 150~300 (PN16~40) |
| Body material | Carbon steel, stainless steel, alloy steel, duplex stainless steel |
| Plug material | SS304, SS316, FKM, PTFE, PPL |
| Bellows material | Stainless steel |
| Options (PRR01) | Seal port V1/V2, impulse tube, valve stem extension |
| Options (PRR02) | Seal port V1/V2, control line, valve stem extension |
When the fluid temperature is 120°C or below, sizes 15~80A can be installed in any orientation. For 100~250A, or when the fluid temperature exceeds 120°C, every size must be installed in a horizontal pipe only. In that case the pressure actuator (the part that receives pressure and moves the valve) faces downward.
On PRR01, the seal port is installed on the impulse tube (the line that carries pressure to the actuator) between the pipe and the control actuator. Apply the seal port in every condition that uses steam and in every condition where the service temperature exceeds 150°C.
The flow coefficient and allowable differential pressure are the same for PRR01 and PRR02. The allowable differential pressure is 1.6 MPa for PN16 and 2.0 MPa for PN40 up to 80A, drops from 100A, and reaches 1.0 MPa for both classes at 250A.
| Size | Flow coefficient | Allowable differential pressure PN16 (MPa) | Allowable differential pressure PN40 (MPa) |
|---|---|---|---|
| 15A | 4 | 1.6 | 2.0 |
| 20A | 6.3 | 1.6 | 2.0 |
| 25A | 8 | 1.6 | 2.0 |
| 32A | 16 | 1.6 | 2.0 |
| 40A | 20 | 1.6 | 2.0 |
| 50A | 32 | 1.6 | 2.0 |
| 65A | 50 | 1.6 | 2.0 |
| 80A | 80 | 1.6 | 2.0 |
| 100A | 125 | 1.5 | 1.5 |
| 125A | 160 | 1.5 | 1.5 |
| 150A | 280 | 1.2 | 1.2 |
| 200A | 320 | 1.0 | 1.0 |
| 250A | 450 | 1.0 | 1.0 |
| Size | L | B | B1 | Weight (kg) | Weight with extension (kg) |
|---|---|---|---|---|---|
| 15A | 130 | 212 | - | 6.2 | - |
| 20A | 150 | 212 | - | 6.7 | - |
| 25A | 160 | 238 | - | 9.7 | - |
| 32A | 180 | 238 | - | 13.0 | - |
| 40A | 200 | 240 | - | 14.0 | - |
| 50A | 230 | 240 | - | 17.0 | - |
| 65A | 290 | 275 | - | 29.0 | - |
| 80A | 310 | 275 | - | 33.0 | - |
| 100A | 350 | 380 | - | 60.0 | - |
| 125A | 400 | 380 | - | 70.0 | - |
| 150A | 480 | 326 | 630 | 80.0 | 140.0 |
| 200A | 600 | 354 | 855 | 140.0 | 210.0 |
| 250A | 730 | 404 | 1,205 | 220.0 | 300.0 |
Unit mm, tolerance ±0.5 mm
Q. Can it be installed where there is no power or compressed air?
A. Yes. Both models are self-acting, so no separate power supply is needed. Depending on the model, connecting lines such as an impulse tube or a control line are required.
Q. What should I base the size selection on?
A. Narrow down candidates by comparing the flow coefficient and allowable differential pressure of each size against the required flow rate, inlet and outlet pressures, and pressure class. The allowable differential pressure drops from 100A, so for larger sizes check the differential pressure condition first.
Q. Can it be used with steam or high-temperature fluids?
A. PRR01 can be applied up to 250°C or below when equipped with a seal port and a valve stem extension. For 15~125A the standard limit is 100°C or below, and 150°C or below with a seal port; for 150~250A the limit is 140°C or below with a seal port. In both ranges, applying a seal port and a valve stem extension together allows 250°C or below. For the service temperature of PRR02, please tell us your fluid conditions and we will check.
Q. How is the downstream piping protected when a pressure reducing regulator is installed?
A. A spring-loaded pressure reducing regulator can generally end up in the open position if its diaphragm fails. Confirm at the design stage that the downstream piping can withstand the upstream pressure, and if it cannot, a common approach is to provide a relief device downstream.
Q. Can PRR02 be used instead of a safety valve?
A. No, it is not used as a substitute. PRR02 is a pressure regulator that holds upstream pressure at a set value, whereas a safety valve is selected as a separate device responsible only for overpressure protection. A spring-loaded upstream pressure regulator can generally close if its diaphragm fails, so a common approach is to provide a separate device that protects the upstream piping.
Other models in the same regulator line are introduced separately by purpose: differential pressure control PDRC01 and PDRO01, temperature control TR01 and TR02, and tank low-pressure control MPR01 and MPR02.
If you provide the information below, it is easier to review the model, size and options.
1. Control purpose: hold downstream pressure (PRR01) or hold upstream pressure (PRR02)
2. Size and connection: bore (A), and whichever of flange, butt weld or socket weld is required
3. Set values: the pressure to control, inlet and outlet pressures, pressure class (ASME Class 150 or 300)
4. Fluid: fluid type including whether it is steam, and temperature
5. Installation conditions: whether the pipe is horizontal, and size
6. Options: whichever of seal port, impulse tube (PRR01), control line (PRR02) and valve stem extension are needed
Purchase and Inquiries
| sales@valvepark.com | |
| Phone | 1666-0215 |
| KakaoTalk Channel | Chat on KakaoTalk |
| Website | Go to the VALVEPARK website |
| Smart Store | Go to the VALVEPARK Smart Store |