Hayward Diaphragm Gasket, EC40/50, ECX1003

The Hayward ECX1003 is the rubber diaphragm gasket for Perflex DE filters. It is the genuine Hayward part, named in the Hayward catalog for the EC40 and EC50.

What it seals

A Perflex filter coats its flex tubes with DE and uses a bump handle to redistribute that coat. The diaphragm gasket is part of the seal that keeps that internal arrangement tight. When it hardens or splits, DE finds its way past and ends up back in the pool as a fine dust on the floor, which owners often mistake for a torn flex tube.

Fitment note

The part name refers to the EC40 and EC50. The gasket is also listed in the parts groups for the Perflex EC30 and EC40 and for the EC50, EC50C, EC50A and EC50AC. Both readings come from the manufacturer information, so compare ECX1003 against the gasket you take out if you are working on an EC30.

Because it is inexpensive and only reachable with the filter open, this is a sensible part to renew whenever you are already in the tank for flex tube or bump shaft work.