Design form of gate valve stem in the pump valve parts: structure of mainly adopts three different bonnet or stem design structure, including the screw lift stem, the non-lift stem and screw thread on the scaffold.
The lower thread lift valve cover/stem design of the pump valve parts is the most commonly used design structure of bronze valves.Because the stem threads are exposed to the medium, potential corrosion damage can result in stem and gate failure.The downward spiral design is not suitable for critical industrial use.
The non-lift stem type in the pump valve parts is a special type used for the restricted use of vertical space above the hand wheel.This is due to the non - lift stem valve when the valve is open and the stem cannot be raised.Currently, most non-lift stem valves are made of iron or bronze.Steel non - lift stem gate valves are used when space is tight (for example, underground operations).
The pump valve parts of the valve stem/bonnet design structure used in the industrial use of threaded brackets.Especially in the corrosive environment, because the thread is far away from the dielectric pollution zone, it is also bound to be away from the potential corrosion.This structure will also, unlike other design structure, the structure of bracket at the top of the hand wheel is and valve sleeve are connected, rather than directly to connect and stem itself, so that no open when the hand wheel is as rise.
One of the pump valve parts is the knife-edge valve and the slide gate valve.The valve - free knife gate valves are especially suitable for the mud environment such as paper mills.Knife gate valves are relatively thin, only slightly wider than the closing parts (disc).Because of the unique geometrical shape and thin section of the knife gate valve, the pump valve parts are also limited to low pressure applications.From the outside, the slide gate valve is not a member of the gate valve family, but is based on the design structure of the slide gate valve, which itself is the characteristic of the gate valve.Mainly used in waste water and flushing system.http://www.dmgcastings.com/