Threaded valve spring Weiqi, Everbright valve (certified), the 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. In the company of the highest quality at the lowest cost of production of goods and services customer safety valve, through the complete elimination of waste in order to achieve "high quality, low cost, short delivery time" to meet customer needs. "Zero defect quality products to our ultimate goal" A21H-C type safety valve, to provide users with a distinguished quality products so that they are satisfied - Everbright Everbright Valve Valve Co., Ltd. Shandong welcome new and old customers call to order! Opening height: leave the valve in the closed position of the actual lift. Flow area: refers to the valve closure member between the inlet end to the sealing surface of the flow channel of the smallest cross-sectional area, is used to calculate the theoretical displacement without any resistance when the impact. Flow channel diameter: diameter of the flow channel is applied to the area. Valve Co., Ltd. Shandong Everbright valve manufacturer specializing in the production, welcome new and old customers to order our products!