Brass Socket - 1/4"

Brass Socket - 1/4"

The Rubber Drain Off Cock Washer TYPE A (Product Code: T1539) is a standard replacement seal used for "Type A" drain-off valves (also known as MT cocks). These valves are typically found at the low points of central heating systems or on radiator valves to allow for system draining.

Key Technical Specifications

Type: Type A (Glanded).

Dimensions: Approximately 14mm x 4.0mm x 2.75mm (dimensions may vary slightly by manufacturer).

Material: Black EPDM Rubber (heat and chemical resistant).

Compatibility: Specifically for Type A valves, which feature a gland packing/stuffing box around the spindle to prevent leaks when the valve is open.

Type A vs. Type B Washers

It is important to ensure you have a Type A valve before purchasing:

Type A (Glanded): Features a nut around the spindle that can be tightened to stop "weeping" while the valve is in use. These are the preferred choice for indoor use.

Type B (Non-Glanded): A simpler, cheaper design often used in locations where a small amount of water loss during operation is acceptable. Type B washers are usually a different size and shape.

Installation Best Practices

Isolate: Ensure the part of the system you are working on is isolated or drained down below the level of the valve.

Removal: Fully unscrew the drain cock spindle. You may need a pair of grips or a small spanner to remove the internal jumper that holds the washer.

Clean: Remove the old, perished washer and clean any debris or limescale from the brass jumper and the valve seat inside the body.

Replacement: Simply stretch or press the new rubber washer onto the jumper and reassemble the valve. Do not over-tighten the valve once replaced, as this can "crush" the new rubber and shorten its lifespan.