The gate is the opening and closing part of the gate valve. Because the moving direction of the gate is perpendicular to the fluid direction, the gate valve can only be fully opened and closed, while the American standard gate valve is simple in shape, short in structural length, good in manufacturing technology and wide in application range. Today, let's take a look at the American standard gate valve standards. And the classification of gate valves.
American standard for gate valves
1. All American standard flange gate valves have characteristics:
1. American standard flange gate valve seats can be more tilting seats, which can be arbitrarily combined and matched with the materials of closing sealing surfaces to meet the requirements of working conditions and prolong the service life;
2. The closing part (gate) adopts elastic structure, which can automatically compensate the valve body deformation caused by abnormal load or temperature during work. Therefore, the seal is reliable, and the ram wedge column will not be generated;
3. the product design and manufacture meet the requirements of American national standard ANSIB16.34, api gravity standard AP16D and API6;
4. Compact structure, small volume, good rigidity and safe and reliable sealing;
5. Manual valves with nominal diameter greater than or equal to NPS111, pressure class 4 and nominal diameter greater than or equal to NPSS611 and pressure class 15-25 are equipped with rolling bearings in their operating devices, making it easy to open and close;
6. The materials of main body, internals, packing, gasket and fastener of American standard flange gate valve can be reasonably combined according to user's requirements or actual working conditions.
ii. design standard of some American standard flanged gate valves:
design and manufacture: API6 API6D GB12234
flange size: ANSIB? 16.5 JB/T79 GB9113
pressure and temperature: ANSSIB? 16.34
structural length: ANSIB16.1 GB12221
butt welding connection size: ANSIB? 16.25
inspection and test: API598 JB/T992
Classification of gate valves
According to the sealing surface configuration, wedge gate valves can be divided into single gate type, double gate type and elastic gate type; Parallel gate valves can be divided into single gate type and double gate type. According to the thread position of the valve stem, it can be divided into two types: open stem gate valve and hidden stem gate valve.
The installation and maintenance of gate valves should pay attention to the following matters:
Handwheels, handles and transmission mechanisms are not allowed to be used for lifting, and collision is strictly prohibited.
the double gate valve should be installed vertically (i.e. the valve stem is in the vertical position and the handwheel is at the top
The gate valve with bypass valve should open the bypass valve before opening (to balance the pressure difference between the inlet and outlet and reduce the opening force).
the gate valve with transmission mechanism shall be installed according to the product instruction manual.
if the valve is frequently opened and closed? ,? Lubricate at least once a month.
through the introduction of xiaobian above, I believe that everyone has a general understanding of American standard gate valve standards. I would like to remind you that there has been such a phenomenon for a long time, that is, gate valves sold in the market will leak or rust. Therefore, you should choose brands with quality assurance when purchasing, and don't be greedy for cheap, so that you can use them with confidence. I hope the above contents will help you.