Large Zero Dead Space Drain Valve, 3" Beaded Pipe, Complete, Stabilizing Pin, 1-1/2" Beaded Pipe Side Arm. The Zero Dead Space flush bottom valve is designed to prevent solids from collecting in the bottom of the vessel. The PTFE drain valve plunger is supplied with a Perfluoro and a TFE encapsulated o-ring for the tip and two Perfluoro o-rings installed on the shaft. The drain valve is connected to the reactor by a unique 3 beaded pipe valve seat that is sealed to the reactor bottom. Chemglass's valve permits total drainage of the vessel contents. The sidearm has a 1-1/2 beaded pipe fitting. PLEASE NOTE: COUPLINGS, HOSE CONNECTIONS AND ADAPTERS ARE SOLD SEPARATELY.