A complete lapping kit which can be used on Tyco, Crosby and Anderson Greenwood Pressure Relief Valves.

Lapping blocks are made of a special grade of cast iron to ensure the best quality in his lifetime. There is a block for each orifice size. Each block has two perfectly flat working sides and it is crucial that the lapping blocks keep their high flatness to produce a flat seating surface on either the disc or the nozzle.