Description
Foot Valves can be added to the suction end of a chemical feed system to aid in maintaining a full and primed suction line. A foot valve can help maintain the prime, keeping the suction line full when performing maintenance. It also prevents the solution from flowing back into the feed tank whenever there is a leak, when pump ball checks are not seated, or when the feed tank runs dry.
Foot valves are generally only required when pulling a suction lift. They use ball checks or spring-loaded ball checks to prevent flow from returning to the tank. Foot valves without springs must be installed vertically.
Foot valves may also contain strainers which will help prevent particles from entering the pump and clogging ball checks or injectors.
Strainers can also be provided without foot valves, when a foot valve is not necessary. Strainers are needed if there is particulate in the solution that can clog ball checks or injection valves (injectors.)
Strainers can simply be a foot valve body without the ball check, or they can be specific element for only that purpose.
Some strainers (Y-strainer, basket strainer) can be installed in-line closer to the pump (for easier service) or mounted on skids as part of a complete system. Ensure the mesh rating of the strainer is appropriate for the application.
Application
Generally, foot valves are recommended and required for diaphragm pumps, but can also be used with peristaltic pumps:
- Diaphragm pumps, or peristaltic pumps, can lose prime when being serviced. The foot valve keeps solution in the suction tubing or piping making it easier to re-prime the pump after service.
- When the feed tank level drops below the foot valve, the solution in the pipe or tube will not be allowed to flow out. The tank can be replaced or refilled without the need to reprime the pump.
- When the diaphragm pump stops pumping and any particulate prevents the ball checks from seating, the solution may have the opportunity to flow back through the pump and back into the feed tank. A foot valve can prevent this.
- Foot valves typically include a strainer to prevent particulates from clogging the pump or other components. If a foot valve is not required because of flooded suction or other reasons, a strainer, or strainer portion of the foot valve, may still be needed for this reason. Solutions that can precipitate or naturally contain small solids will require a strainer. Be sure to monitor or clean strainers frequently, as clogged strainers will starve the pump and prevent it from pumping accurately or at all.
Installation and Maintenance
Foot valves and strainers are installed at the end of the tubing or piping that is placed in the chemical feed tank. Use of rigid pipe is recommended to keep the foot valve vertical. If using tubing, secure the tubing or provide weight to keep the foot valve vertical. Some foot valves include springs to keep the ball seated and may not need vertical placement. The foot valve is best located a few inches from the bottom of the tank to prevent settled solids from being pulled into the flow. Ensure the installation of the piping or tubing in the tank is easily serviced or removed when necessary.
Some y-strainers are designed to be piped in-line. Ensure flow and pressure specifications are proper for the application. Ensure these are installed in the correct flow direction with Y end pointed downward (if installed horizontally). Ensure there is enough space below the strainer for service and cleaning.
Ordering Information
Materials available: PVDF bodies. EPDM or FKM O-rings. Ceramic balls (unless stated otherwise).
Connection types: ¼”x3/8” compression, ½” hose barb, ½” NPT, and ½” socket (in-line).
| Part number | Description | Material (Body/O-ring) | Spring |
| Foot Valves | |||
| C-340A | Foot Valve, PVDF(black)/FKM, ¼”x3/8” tube connection | PVDF/FKM | none |
| C-340E | Foot Valve, PVDF(black)/EP, ¼”x3/8” tube connection | PVDF/EP | none |
| C-340A-P | Foot Valve, PVDF(black)/FKM, ¼”x3/8” tube connection (PTFE Ball) | PVDF/FKM (PTFE ball) | none |
| 71010-261 | Foot Valve, PVDF(black)/FKM, ¼”x3/8” tube connection | PVDF/FKM | 1/2 psi |
| 71001-106 | Foot Valve, PVDF/FKM, ¼”x3/8” tube connection | PVDF/FKM | 2 psi |
| 71001-107 | Foot Valve, PVDF/EP, ¼”x3/8” tube connection | PVDF/EP | 2 psi |
| 71001-607 | Foot Valve, PVDF/FKM, ¼”x3/8” tube connection (PTFE Ball) | PVDF/FKM (PTFE ball) | 2 psi |
| 71000-575 | Foot Valve, PVDF/FKM, ½” Hose Barb | PVDF/FKM | 2 psi |
| 71000-576 | Foot Valve, PVDF/EP, ½” Hose Barb | PVDF/EP | 2 psi |
| 71001-005 | Foot Valve, PVDF/FKM, ½” Hose Barb (PTFE Ball) | PVDF/FKM (PTFE ball) | 2 psi |
| 71000-849 | Foot Valve, PVDF/FKM, ½” MNPT | PVDF/FKM | 2 psi |
| 71000-850 | Foot Valve, PVDF/EP, ½” MNPT | PVDF/EP | 2 psi |
| 71001-280 | Foot Valve, PVDF/FKM, ½” MNPT (PTFE Ball) | PVDF/FKM (PTFE ball) | 2 psi |
| Foot Strainer | |||
| C-340X | Strainer, PVDF(black), ¼”x3/8” tube connection | PVDF | N/A |
| 71000-825 | Strainer, PVDF, ½” hose barb | PVDF | N/A |
| 71000-824 | Strainer, PVDF, ½” MNPT | PVD | N/A |
| C-342-6 | Strainer (1/4” ID tubing) | PVDF | N/A |
| C-346 | Ceramic Weight (3/8” OD tube) | ||
