A multiple valve assembly incorporates three valves in one valve body. The main body has inlet and outlet ports in the mainline, and two sample ports, one on either side of the main valve seat. The valves and sample ports are oriented in only two planes for easy installation and access....http://www.google.fr/patents/US5449294?utm_source=gb-gplus-shareBrevet US5449294 - Multiple valve assembly and process
