Check valves prevent reverse flow, but steam and condensate applications place special demands on the closing mechanism, seal, installation position and pressure-temperature rating. Valsteam ADCA offers three compact options for common steam-system duties: RT25, RD40 and SCKi.
RT25 threaded disc check valve
The ADCA RT25 is an all-stainless-steel disc check valve for saturated steam, water and compatible gases or liquids. According to Valsteam, it is available from 1/4 to 2 inch with ISO 7 Rp or NPT female threads, up to 21 bar operating pressure and 220°C.
The spring pushes the disc toward the seat. Forward differential pressure opens the valve; spring force plus downstream pressure closes it when flow reverses. With a spring, it may be installed in different positions. Without a spring, Valsteam restricts installation to vertical upward flow.
RD40 wafer check valve
The RD40 is an all-stainless-steel wafer disc valve installed between EN 1092 or ASME flanges. The DN15–DN100 version is rated up to 40 bar and 300°C within its pressure-temperature envelope. A DN125–DN200 range is also listed. Its compact face-to-face dimension and low pressure drop suit larger steam and hot-condensate lines.
Soft-seat options include EPDM, NBR, FPM and PTFE, but temperature limits vary by material. Seal compatibility must be checked against the fluid, cleaning chemicals and maximum temperature.
SCKi sight checker
The SCKi combines a sight glass and check valve downstream of a steam trap. It lets operators observe discharge while limiting condensate backflow. Valsteam lists 1/2 to 1 inch threaded sizes, 10 bar maximum operating pressure and 150°C maximum operating temperature. Its information sheet recommends locating it at least one metre from the trap to protect the glass from thermal shock.
Selection summary
| Model | Best fit | Connection |
|---|---|---|
| RT25 | Compact threaded steam and condensate service | Rp or NPT |
| RD40 | Larger flanged pipelines with short face-to-face requirement | Wafer between flanges |
| SCKi | Trap discharge observation plus non-return function | Rp or NPT |
Consult the official Valsteam product page and current model sheet before specification. For Indian projects, contact PureSys India with size, pressure, temperature, connection and flow direction.
