O-Rings
Sealing Technology
O-rings seal the joints of a data centre chilled water distribution wherever the sealing face is compressed axially: PVC-U union nuts, strainer caps, connections on manifolds. The category holds 26 items from Fluidics equipment and Riegler. It covers the PVC-U sizes 20, 25, 32, 40, 50, 63, 75 and 90 mm with a cord thickness of 3.53 or 5.33 mm, plus O-rings for gunmetal strainers from DN 8 to DN 40 with ports from G 1/4 to G 1 1/2.
Compound choice decides service life. In a water-glycol loop EPDM is the right answer: it resists water, hot water and aqueous glycol mixtures and keeps its recovery force. FKM belongs with oils, fuels and aggressive chemicals but loses strength in hot water and glycol, and NBR is a pure oil and compressed air material. Order the EPDM version for cooling duty and keep the FKM variant of the same size for media outside the loop.
O-rings for PVC-U unions - size, dimension and compound
| Size | Inside diameter x cord | Compound supplied | Use in the cooling loop |
|---|---|---|---|
| 20 mm | 20.22 x 3.53 mm | FKM | outside the water-glycol loop only |
| 25 mm | 28.17 x 3.53 mm | FKM | outside the water-glycol loop only |
| 32 mm | 32.92 x 3.53 mm | FKM | outside the water-glycol loop only |
| 40 mm | 40.65 x 5.33 mm | FKM | outside the water-glycol loop only |
| 50 mm | 47.0 x 5.33 mm | EPDM | suitable |
| 63 mm | 59.7 x 5.33 mm | EPDM | suitable |
| 75 mm | 78.74 x 5.33 mm | EPDM | suitable |
| 90 mm | 91.44 x 5.33 mm | EPDM | suitable |
- Resealing PVC-U union nuts in a chilled water distribution
- Removing and reconnecting pipe runs: always fit a new O-ring, never reuse the old one
- Gunmetal strainers: renew the cap seal after every screen cleaning
- Connecting coolant distribution units to an existing PVC-U network
- Converting a loop from oil or chemicals to water-glycol: swap FKM rings for EPDM
- Spare stock for maintenance windows that leave no room for delivery time
