Heavy steel casting off valve J41H-16C

Works shut-off valve, also known as stop-gates, is the most widely used of a valve, the reason it's popular is due to the process of opening and closing between the sealing surface friction is small, more durable, opening height is not easy to manufacture , easy maintenance, not only for low-voltage, and suitable for high pressure. Cut-off valve is closed principle, relying on the valve bar pressure, so the valve sealing surface and the valve seat provides tight fit, to prevent the media circulation. Shut-off valve can only medium-way flow, directional installation. Structural length is greater than the cut-off valve gate, while the fluid resistance, long-term operation, the sealing reliability is not strong. Classification according to the channel direction shutoff valve 1) straight-off valve 2) DC-type valve: DC-type or Y-shaped valve, the valve body of the flow channel and the main channel into a slash, so the damage flow state than conventional cut-off valve should be small, and thus the pressure loss through the valve is correspondingly smaller. 3) angle type valve: in angle-type valve, the fluid simply by changing a direction, so that the passage of the valve shut-off valve pressure drop than the conventional structure. American Standard bellows valve zdaj41w type 4) plunger-type valve: This form of cut-off valve is a variant of the conventional cut-off valve. In the valve, the valve and seat are usually designed based on the plunger principle. Polished into a flap valve stem is connected with the plunger seal is set on the plunger two elastic seals to achieve. Two elastic rings separated by a collar, and through the valve cover nut load exerted on the valve cover seals around the plunger pressure prison. Elastic ring can be replaced, you can use a variety of materials, the valve is mainly used in the "on" or "off", but with a special form of plunger or special rings, can also be used to regulate the flow . According to the cutoff valve stem threads on position 1) on the threaded stem valve: shutoff valve stem threads on the outside of the valve body. The advantage is that the erosion of the stem from the media, easy lubrication, such a structure using more common. 2) lower threaded stem valve: threaded globe valve stem in the valve body. This structure stem threads in direct contact with the media, prone to erosion, and can not be lubricated. Such a structure for small caliber and the temperature is not high places. Domestic production of cut-off valve of the manufacturers are more connected mostly non-uniform size. Mainly divided into the following categories: 1) JB / T2203-1999 "shut-off valve structure length" based utility category. Currently most of the safety valve manufacturer in accordance with this standard design and production. As Highline Le Valve Co., Ltd., Zhejiang Luofu Boiler Accessories Factory, Hangzhou shutoff valve factory, good public Valve Co., Ltd. Shanghai, Shanghai shutoff valve plant, Kaifeng High-pressure valve plant, MSC shutoff valve factory. But the standards are not perfect, incomplete specifications, single gate shut-off valve maximum nominal diameter of DN1200, double plate shutoff valve maximum nominal diameter DN1500. According plant produced by the cut-off valve specifications and the information available, the current angle type valve nominal diameter minimum DN15, Z-type straight-off valve nominal diameter to DN2000. The research, the manufacturers are not the unified connection dimensions, such as DN150Z straight-through-type valve, Shanghai Liang valve factory congregation, Shanghai factory shut-off valve and valve plant on Haiya Ze vary. In order to have a uniform standard, the user in the selection and installation of the same specification to exchange, suggested that China General Machinery Research Institute of JB / T2203-1999 "shut-off valve structure of length" be revised. Proposed institute and the user selected standard, globe valve manufacturer according to standard design and manufacturing.