Weiqi threaded valve | Everbright valve (certified) | safety valve provided by Shandong China Everbright Limited valve. Valve Co., Ltd. Shandong China Everbright (www.sdgdfm.com) is specialized in the "valve" of the enterprise, the company of "honesty, hard service" concept, to provide you with the highest quality products and services. Welcome to inquire! Contact: Manager Ma. Back seat pressure: After re-contact discharge valve spring Weiqi A21F threaded valve and valve seat, namely opening height becomes zero the inlet pressure. Blowdown: opening pressure and the pressure difference between the back seat A21H-C-type valve, usually a percentage of the back seat, said pressure relief valve opening pressure only when using the pressure difference between the two to represent the opening pressure is low. Valve Co., Ltd. Shandong Everbright valve manufacturer specializing in the production, welcome new and old customers to order our products! Displacement Theory: equal flow path cross-sectional area and flow area valve ideal nozzle displacement calculation. Displacement factor: the actual and theoretical displacement displacement ratio. Rated discharge coefficient: discharge coefficient and reduce the coefficient (0.9) of the product. Valve Co., Ltd. Shandong Everbright valve manufacturer specializing in the production, welcome new and old customers to order our products!