Watts
Compatible O-Ring for Membrane Housing Sump
$5.49
This precision O-ring creates a watertight seal for the sump of most reverse osmosis membrane housings with 1/8" FPT caps that accept standard membranes. Built to AS568-139 specifications with 2-3/16" ID × 2-3/8" OD × 3/32" cross-section, it fits Watts 020-MVH90 and compatible membrane housings.
TECHNICAL DETAILS
O-Ring Specifications
| Standard | AS568-139 O-Ring |
| Inside Diameter (ID) | 2-3/16 inches |
| Outside Diameter (OD) | 2-3/8 inches |
| Cross Section (CS) | 3/32 inch |
| Application | Membrane housing sump seal |
| Housing Cap Thread | 1/8" FPT |
| Vendor | Watts |
COMPATIBILITY & APPLICATIONS
What This O-Ring Fits
This O-ring seals the sump (lower housing) of reverse osmosis membrane housings that accept standard-size membranes, including the Watts 020-MVH90 and similar RO membrane vessels with 1/8" FPT cap threads. It's designed for the housing body itself, not the cap. If you need the O-ring for the membrane housing cap, use Watts part number 143484 instead. Compatible with most residential RO systems using standard 1.8" × 12" membranes in housings with threaded caps.
💧 Replace both the sump and cap O-rings together during membrane changes to prevent leaks and maintain optimal system performance.
