The Sterile Barrier block addresses the issues of achieving sterile barrier technology and utilizing a small dimensional envelope while minimizing contact surfaces and hold up volume. The Integral Sterile Barrier consists of four valves machined from a single block. The common chamber is located in the center of the block and the independent ports are located on the ends. The assemblies consist of two product valves, a steam injection valve and a condensate drain valve. When the two product valves are open and the steam injection and condensate valves are closed, product flows through to the reactor. When the product valves are closed, a chamber is formed between the two valves which, when injected with steam, provides a sterile barrier isolating the reactor.