Supply quality assurance j41h-16c carbon steel stop valve DN2 hot selling product

brand:	Jiashang valve
model:	dn15-dn200
connection form:	flange
material:	carbon steel
nominal diameter:	dn15-dn200 (mm)
applicable medium:	weak acid-base medium
pressure environment:	normal pressure
working temperature:	normal temperature
standard:	National Standard
shape:	medium
flow direction:	bidirectional
driving mode:	manual
parts and accessories:	Accessories
form:	plunger type
type (channel position):	two-way type
specification:	DN32 * 25C, DN65 * 25C, DN150 * 16C, DN125 * 16C For other models, please inquire customer service, DN80 * 25C, DN150 * 25C, DN25 * 25C, DN20 * 25C, DN200 * 25C, DN65 * 16C, DN100 * 16C, DN200 * 16C, The opening and closing parts of Dn40 * 25C, DN15 * 25C, DN50 * 25C, DN100 * 25C, DN125 * 25C

stop valves are plug-shaped disc, the sealing surface is flat or conical, and the disc moves in a straight line along the center line of the fluid
The movement form of valve rod (general name: concealed rod) also has lifting rotary rod type (general name: exposed rod)
Stop valve refers to the valve whose closing part (disc) moves along the centerline of the valve seat
According to this movement form of the disc, the change of the valve seat opening is in direct proportion to the disc stroke
Because the opening or closing stroke of the valve stem of this kind of valve is relatively short, and has a very reliable cut-off function, and because the change of the valve seat opening is directly proportional to the stroke of the valve disc, it is very suitable for the regulation of flow
Therefore, this type of valve is very suitable for cut-off or regulation and throttling The stop valve is a forced sealing valve, so when the valve is closed, pressure must be applied to the valve disc to force the sealing surface not to leak
When the medium enters the valve from below the valve disc, the resistance to be overcome by the operating force is the friction between the valve stem and packing and the thrust generated by the pressure of the medium
The force to close the valve is greater than the force to open the valve, so the diameter of the valve stem should be larger, otherwise the failure of valve stem jacking will occur
In recent years, after the emergence of self sealing valve, the medium flow direction of stop valve changes from above the valve disc to enter the valve cavity
At this time, under the action of medium pressure, the force to close the valve is small, while the force to open the valve is large, and the diameter of valve rod can be reduced accordingly
At the same time, under the action of medium, this form of valve is also more tight
Valves in China & ldquo; Three to & rdquo; It has been stipulated that the flow direction of the stop valve shall be from top to bottom
The valve shall be installed horizontally
When the stop valve is opened, when the opening height of the valve disc is 25% ~ 30% of the nominal diameter, the flow has reached the maximum, indicating that the valve has reached the fully open position
Therefore, the full open position of the stop valve shall be determined by the stroke of the valve disc
Working principle of stop valve: , Stop valve, also known as shut-off valve, is the most widely used valve
Its popularity is due to the small friction between sealing surfaces during opening and closing, relatively durable, small opening height, easy manufacture and convenient maintenance
It is not only suitable for medium and low pressure, but also suitable for high pressure
The closing principle of the stop valve is to make the sealing surface of the valve disc closely fit the sealing surface of the valve seat by relying on the pressure of the valve rod to prevent the medium from flowing
The stop valve only allows one-way flow of medium and has directionality during installation
The structural length of the stop valve is longer than that of the gate valve, and the fluid resistance is large
During long-term operation, the sealing reliability is not strong
1） Advantages
  1
The utility model has the advantages of simple structure and convenient manufacture and maintenance 2
Small working stroke and short opening and closing time 3
Good sealing performance, small friction between sealing surfaces and long service life

2） Disadvantages , 1
The fluid resistance is large, and the force required for opening and closing is large 2
It is not suitable for media with particles, high viscosity and easy coking 3
Poor regulation performance 4
The fluid resistance is large, and the sealing reliability is not strong during long-term operation The types of stop valves are divided into external thread type and internal thread type according to the position of valve stem thread According to the flow direction of the medium, there are straight through type, DC type and angle type The stop valve is divided into packing seal stop valve and bellows seal stop valve according to the sealing form Precautions for structure and installation:
3） Structural form of stop valve , The structural forms of stop valve body include straight through type, DC type and right angle type
Straight through type is the most common structure, but its fluid resistance is the largest
Direct flow fluid has low resistance and is mostly used for fluids with solid particles or high viscosity
The right angle valve body is mostly forged, which is suitable for globe valves with small passage and high pressure
4） The installation and maintenance of stop valve shall pay attention to the following matters , 1
The hand wheel handle operated stop valve can be installed at any position of the pipeline 2
Handwheel handle and servo mechanism are not allowed to be used for lifting 3
The flow direction of medium shall be consistent with the arrow direction shown on the valve body 5） Product details display
6） Warehouse display
7） Workshop display