Back Pressure Regulating Relief Valve
This pressure control valve is used for very high back pressure control applications such as maintaining constant pump discharge pressures, bypassing excessive pressures from various types of process equipment, and wherever a constant pressure must be maintained in a process or piping system. Because of the needle nose piston, this valve is also used for relieving high pressures at very low flows. The 303 stainless steel valve can be used for non-corrosive or mildly corrosive fluids, but can be upgraded to 316SS or even Hastelloy C276, Titanium, Monel or even Tantalum for very agressive applications. Use only clean filtered or strained liquids or gases to remove debris or other solid matter that might cause internal clogging or improper operation of this precision machined valve. Install a filter or strainer with a fine wire mesh (at least #20 mesh) before the inlet of the back pressure valve. High-pressure in-line strainer fittings, basket strainers, and fine wire mesh filtes can be purchased from Stra-Val.
When used with high pressure air or gases, the thermal effects of rapid expansion need to be considered, especially if moisture is present in the gas which could result in the valve freezing up and making it temporarily inoperable while in a frozen state. Several preventative measures may need to be considered, such a moisture removal, limiting pressure reduction in stages, or even heating the valve and related piping.
Standard metal seated valves meet ANSI/FCI Class IV seat leakage standards (0.01% of rated valve capacity, not bubble tight). For low pressure applications, a PTFE seat can be ordered to improve the shutoff class compared to a normal metal seat.
Select from the material options displayed below. Other options available, but not not priced, are:
- Panel Mounting,
- Hand wheel or hand knob
- Locking cap
- Hardened Piston and seat
Principle of Operation
This is a direct-acting back pressure-relief valve with an adjustable spring operating against a piston subjected to the inlet pressure of the valve. Increasing the spring compression will increase the system or line pressure to be maintained. Reducing the spring compression will reduce this pressure. An increase in system pressure beyond the set point will cause the piston to open and relieve the excess pressure through the outlet port of the back pressure relief valve. The needle nose piston results in very smooth pressure control not possible with large orifice, flat nose pistons designed for quick pressure release
|1.||Adjusting screw||Steel & SS|
|2.||Lock nut||Steel & SS|
|3.||Spring chamber||Steel & SS|
|4.||Spring pusher||Steel & SS|
|5.||Adjusting spring||Steel & SS|
|6.||Spring Carrier||Steel & SS|
|7.||Piston||Stainless steel & Custom alloys|
|8.||Seal||Viton, EPDM, Teflon*, Kalrez*, etc.|
|9.||Body||Stainless steel & Custom alloys|
*Registered DuPont materials
Dimensions ( inches)
|A||B||C||D||Max inlet PSI (Bar)|
Note: Dimensions are approximate and are subject to change without notice. Request certified dimensions before final product installation.
To show prices:
Click on a size:
|1/4" BPH05-02T||3/8" BPH05-03T||1/2" BPH05-05T||3/4" BPH05-07T|
To price or order, first select a size above.
Please enter the number of units and choose the Factory Set pressure (value must fall within the selected spring range) or select "None (valve set by customer)."
To enter multiple values with different set pressures, simply add rows to this form and specify a quantity and value for each row. The total number of units specified here will determine the overall quantity for your shopping/quotation cart. These steps are used for pricing only and do not require a purchase.
When an order is placed these set pressures will be laser engraved onto the valve nameplate. If "None" is selected the valves will be factory set to the low end of the spring range or near zero. Final adjustment will be required by the user after installation.