Check Valves
Shut-Off, Control and Safety Valves
A check valve lets coolant pass in one direction only and closes by itself as soon as the flow reverses. In a data centre it sits downstream of pumps and where risers tie into the header, so that a circuit taken out of service is not back-fed. The group holds 623 items: inline RUCK check valves in brass with a G 1/4 female thread rated PN 40, angle-seat versions such as RUCK 34 SS ES in stainless steel with G 3/4 and PN 40, full-bore valves, and one-way flow control valves of the Blue Series.
Three points drive the choice: body style, cracking pressure and material. An angle seat turns the flow less sharply and costs less pressure drop than an inline seat, while full-bore versions crack open at 0.01 to 0.03 bar and suit circuits with little pump head to spare. Stainless steel is the uncritical choice for water-glycol, brass only where the material pairing stays consistent. The Blue Series flow control valves with 10 and 12 mm push-in ports belong in compressed air and control lines, not in the cooling circuit.
Check valves by design, rating and material
| Criterion | Inline RUCK (brass) | Angle seat RUCK SS ES (stainless) | Full bore | Blue Series flow control |
|---|---|---|---|---|
| Connection in stock | G 1/4 female | G 3/4 | G 1 | G/R 1/4 to 1/2 onto 10 and 12 mm |
| Pressure rating | PN 40 | PN 40 | per version | pneumatic range |
| Cracking pressure | per version | per version | 0.01 to 0.03 bar | not relevant |
| Material | brass | stainless steel | brass | nickel-plated brass |
| Fit for water-glycol | single-alloy only | unrestricted | single-alloy only | not intended |
- Backflow protection downstream of circulation pumps in redundant cooling circuits
- Tying individual rack circuits into a shared header
- Protecting circuits that are switched off against backflow from the running plant
- Separating supply and return on heat exchangers connected in parallel
- Securing the make-up line against coolant being pushed back
- Speed control of pneumatic actuators through one-way flow control valves
