Vacuum Check Valve Any Direction
Model: KF40CV80S
KF40CV80S is a spring-loaded vacuum check valve installable in either vertical or horizontal orientations. With a CF8M (316) body and VITON seal combination, it offers an operating temperature of -5 to 100°C, a leak rate of 1×10⁻⁸ mbar·L/s, and a minimum opening differential pressure of approximately 7 mbar, and is used for backflow prevention in vacuum systems in semiconductor, display, solar, and laboratory applications.
Features
- Used to prevent backflow in air, inert gas, and vacuum environments
- Maintains vacuum protection - usable in low-pressure piping conditions
- Internal spring allows vertical or horizontal installation regardless of gravity
Specifications
| FLANGE | KF(NW) |
| MATERIAL | BODY: CF8M(316) / SEAL: VITON |
| TEMP RATE | -5°C~100°C |
| LEAK RATE | 1x10⁻⁸ mBAR L/SEC |
| PRESSURE RANGE | 1x10⁻⁸ mBAR |
| RELIEF MINIMUM PRESSURE Δ P | 7mBAR |
| PEA PUMPING SPEED | 10000(L/MIN) |
| INSTALLATION POSITION | ANY |
Frequently Asked Questions
- Can the check valve be installed horizontally instead of vertically?
- KF40CV80S has an internal spring, so it does not rely on gravity and can be installed in any direction, vertical or horizontal. While typical gravity-dependent check valves only allow vertical installation, this product allows free orientation matched to the piping layout, making it useful in compact equipment or sections with complex piping.
- What does the minimum opening differential pressure of 7 mbar mean?
- For a check valve to pass fluid in the forward direction, a minimum differential pressure sufficient to overcome the spring force is required. The KF40CV80S spring is set to open at approximately 7 mbar of differential pressure, which is easily achieved under normal pumping conditions, so the valve operates without flow restriction. In lines that must operate at very low differential-pressure levels, this opening pressure can become an important design parameter.
- What happens if the operating temperature range is exceeded?
- The standard specification supports the -5 to 100°C range. In high-temperature environments exceeding this range, the VITON seal can harden and lose elasticity, reducing sealing performance. For high-temperature lines, heat-resistant seal materials (such as Kalrez) or metal-sealing structures must be considered. Tell us your operating temperature and we will advise on suitability and alternatives.
- How much does it affect pumping speed?
- KF40CV80S is designed for use even in large-volume pumping lines around 10,000 L/min, and because the minimum opening differential pressure is as low as approximately 7 mbar, its impact on pumping speed under normal operation is limited. However, actual loss varies depending on pump type and piping configuration, so for applications with strict pumping-speed requirements, share the configuration of the applied line and we will review it together.