For extreme, extended pressure (for instance, where home-made seals have popped out of the line), we recommend our standpipe models. The 4" Standpipe Flood-Guard is threaded to receive 1-1/2" I.P.S. pipe. Gaskets are made of molded rubber, and all metal parts are plated, except for wires and float rod, which are solid brass. 4". No. S-4FH: Pipe Size: 4" Thanks for shopping Hipp Hardware Plus's Online Store for all your DIY and Home Improvement needs. Remember Hipps Help!