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You can also review the documentation for technical details and purchasing information.
- M-Series (BPM) Datasheet
- G-Series (BPG) Datasheet
- High Flow (BPHF) Datasheet
- Unibody (BPU) Datasheet
- Solid PTFE Flanged (BPGTF) Datasheet
- Medium Pressure (BPMP) Datasheet (imperial)
- M-Series Installation Manual
- G-Series Installation Manual (DN 15 – DN 50)
- G-Series Installation Manual (DN 80 & DN 100)
- High Flow Installation Manual
GRIFFCO Back Pressure Valves
- Product Details
- Specifications
- Applications & Features
GRIFFCO Back Pressure Valves
Steady, Accurate Dosing and No Siphoning
A back pressure valve goes in the discharge line of a dosing pump, close to the injection point. It stays shut until the line reaches its set pressure, so the pump always pushes against the same pressure and every stroke delivers the same amount of chemical.
It also stops chemical siphoning through the pump or draining out of the line when the injection point is lower than the tank or at low pressure, such as dosing into an open tank or drain.
Inside, a spring holds a PTFE-faced diaphragm against a seat. The set pressure is adjusted with a screw under the cap; valves leave the factory set at 3.5 bar.
Which Series?
- M-Series (BPM) – small dosing pumps, DN 8 – DN 15
- G-Series (BPG) – the main range, DN 15 – DN 100
- High Flow (BPHF) – larger flows, continuous-flow pumps and thick chemicals
- Unibody (BPU) – one-piece PVC or CPVC body with union ends, DN 15 – DN 25
- Solid PTFE Flanged (BPGTF) – sulphuric acid and other aggressive chemicals
- Medium Pressure (BPMP) – all-metal, for 7 – 55 bar systems
Bodies come in PVC, CPVC, PP, PVDF, PTFE, Halar and metals (316 SS, Alloy 20, Hastelloy C), with BSP threads, metric socket, union and flange ends available.
Standard Series
| Item | M-Series (BPM) | G-Series (BPG) | High Flow (BPHF) | Unibody (BPU) |
|---|---|---|---|---|
| Sizes | DN 8 – DN 15 (¼" – ½") | DN 15 – DN 100 (½" – 4") | DN 15 – DN 50 (½" – 2") | DN 15 – DN 25 (½" – 1") |
| Connections | Threaded, socket, union, flange | Threaded, socket, union, flange (DN 80 & 100 flanged only) | Threaded, socket, union, flange | Union socket ends |
| Body Materials | PVC, CPVC, PP, PTFE, PVDF, 316 SS, Alloy 20, Hastelloy C | PVC, CPVC, PP, PTFE, PVDF, Halar, 316 SS, Alloy 20, Hastelloy C | PVC, CPVC, PP, PTFE, PVDF, Halar, 316 SS, Alloy 20, Hastelloy C | PVC, CPVC |
| Diaphragm | PTFE/EPDM standard; Viton, Hypalon, PTFE/Viton and others optional | |||
| Set Pressure (standard spring) | 1 – 10 bar, factory set at 3.5 bar | |||
| Optional Springs | 0.7 – 3.5 bar; 1 – 17 bar; 3.5 – 25 bar (metal valves) | 0.7 – 3.5 bar; 1 – 17 bar; 3.5 – 25 bar (metal, up to DN 25) | 0 – 3.5 bar; 1 – 17 bar | 0.7 – 3.5 bar |
| Maximum Pressure | 25 bar plastic; 138 bar metal | 25 bar plastic; 135 bar metal | 25 bar plastic; 135 bar metal | 15.5 bar |
| Maximum Temperature | PVC 60 °C; CPVC, PP 90 °C; PTFE, PVDF, metal 150 °C | PVC 60 °C; CPVC, PP 90 °C; PTFE, PVDF, metal 150 °C | PVC 60 °C; CPVC, PP 90 °C; PTFE, PVDF, metal 150 °C | PVC 60 °C; CPVC 90 °C |
Special Series
| Item | Solid PTFE Flanged (BPGTF) | Medium Pressure (BPMP) |
|---|---|---|
| Sizes | DN 15 – DN 25 (½" – 1") | DN 8 – DN 25 (¼" – 1") |
| Connections | Flanged | Threaded (NPT, BSPT), socket, flange (from ½") |
| Body Materials | Solid machined PTFE, no glued joints | 316 SS, Alloy 20, Hastelloy C, titanium |
| Diaphragm | PTFE/EPDM standard; Viton, Hypalon, PTFE/Viton optional | PTFE/EPDM standard; Viton, Hypalon, PTFE, PTFE/Viton optional |
| Set Pressure | 1 – 10 bar standard; 0 – 3.5 bar optional | 7 – 55 bar (100 – 800 psi), factory set at 17 bar |
| Maximum Pressure | 25 bar | About 138 bar (2,000 psi) |
| Maximum Temperature | 148 °C | About 149 °C (300 °F) |
Applications
- Discharge line of diaphragm and piston dosing pumps
- Dosing into open tanks, drains, channels or downhill lines, where the line would otherwise siphon
- Chlorine, acid, caustic, coagulant and other chemical feed
- Water and wastewater treatment, process water and cooling towers
- High-pressure injection into mains or boilers (Medium Pressure series)
- Chemical dosing skids
Key Features
- Steady back pressure for accurate, repeatable dosing
- Anti-siphon protection
- Adjustable set pressure, factory set at 3.5 bar
- Optional springs for set pressures from 0.7 bar up to 25 bar, and to 55 bar on the Medium Pressure series
- PTFE-faced diaphragm as standard; Viton, Hypalon and other options to suit the chemical
- Wide choice of body materials, plastic and metal
- Threaded (BSP or NPT), socket, union and flanged ends
- Diaphragm can be serviced without removing the valve from the line
- Made in the USA; NSF/ANSI 61 certified in PVC
Installation Tip
Fit the back pressure valve as close to the injection point as possible. A pulsation dampener and pressure gauge go between the pump and the back pressure valve, and a pressure relief valve protects the pump.
