Oil & Gas Plant Engineers India Private Limited manufactures Voparire Liquid Petroleum Gas Air Mixers. Oil & Gas Plant Engineers India Private Limited is an ISO 9001:2000 registered company. Voparire Liquid Petroleum Gas Air Mixers are basically used as stand-by system for replacement of Natural Gas or Peak Shaving for base load applications. Voparire Liquid Petroleum Gas Air Mixers is a Venturi type of LPG air mixer which can be used for gas delivery pressure upto 15 Psig. Maximum. The equipment basically works on a venturi design through which LPG vapours enter at a high pressure creating vacuum and thereby sucking in air from the atmosphere to give desired diluted gas.