Internal thread ammonia stop valve
Alternative name: threaded ammonia stop valve, threaded liquid ammonia stop valve, pipe thread ammonia stop valve
Model: AJ11F-25 AJ15F-25
Overview of stop valve for internal thread ammonia:
The internal thread ammonia stop valve rotates the hand wheel clockwise, and the valve rod drives the valve disc (opening and closing parts) down until the sealing ring at the lower end of the valve disc closely fits with the sealing surface of the valve body seat, thus cutting off the passage to the closed state. Rotate the hand wheel counterclockwise, the valve rod drives the valve disc to rise, and the passage is opened immediately until the sealing cone above the valve rod is in contact with the sealing line at the lower end of the valve cover, that is, it is fully opened.
Technical parameters of stop valve for threaded ammonia:
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Product specification
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DN15～DN25
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Nominal pressure
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2.5MPa
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Connection mode
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Internal thread
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Applicable temperature
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-30℃~120℃
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Drive mode
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Manual
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Manufacturing standard
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GB/T26478 and JB/T7245
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Installation and adjustment method of ammonia stop valve packing (packing):
The effective sealing of the valve depends on the overall condition of each component. Special attention should be paid to the packing, which is a necessary key component to ensure the leakage of the valve. The valve needs to adjust or replace the packing for many times in its life. Before the packing adjustment and installation, it should be ensured that the valve that needs to replace the packing has been effectively identified and isolated according to the site and system.
There are generally two kinds of fillers used in our products. One is to make composite polytetrafluoroethylene molding filler, which is based on polytetrafluoroethylene, adding flexible graphite and some metal elements to enhance its wear resistance, self-lubricating and other properties, effectively extending the service life of the filler. It is suitable for the temperature range of - 30 ℃~+120 ℃, and fully meets the use of ammonia system. The other is the flexible graphite packing ring, which is made by cutting the flexible graphite plate into strips or winding the flexible graphite braided packing in the mold and pressing. This ring has excellent resilience and stability, and is applicable to the temperature range of - 39 ℃~+150 ℃. Even under more severe conditions, the flexible graphite packing is very stable and reliable.
The following contents are used to guide the maintenance personnel, engineers and assemblers to correctly install and adjust the packing.
Adjustment of packing after installation of ammonia stop valve
In order to effectively extend the service life of the packing, our products have not pressed the packing to death before leaving the factory. Therefore, after the valve is installed, it should be properly adjusted according to the actual service pressure and temperature of the valve.
During the system pressurization test, properly adjust the compression nut, and do not press the packing too tightly. It is better to make the valve stem rotate flexibly (it is very wrong to think that the tighter the packing is, the better. First, it will accelerate the wear of the packing and valve stem, and second, it will reduce the adjustment amount of the packing).
It is suggested that the valve for low-pressure system should be slightly preloaded with the packing during the pressure test (if there is leakage, all valves can be opened, and the upper seal can be used to maintain the pressure), and the system should be adjusted after the ammonia filling.
Packing adjustment of liquid ammonia stop valve during use
Leakage at the stuffing box is a necessary and necessary item for daily inspection. In addition to daily inspection, it is also necessary to check and timely find and dispose at any time to prevent accidents. When slight leakage is found, the compression nut can be adjusted properly to avoid leakage.
Filling and replacement of ammonia stop valve during use
The valves produced by our company are all equipped with upper seals, which can add or replace the packing without stopping the machine.
Filling of special ammonia stop valve
When the packing is compressed too low or there is no adjustment margin, it can be solved by increasing the packing.
Shanghai ammonia valve manufacturers have long supplied internal thread ammonia stop valves, threaded ammonia stop valves, welded liquid ammonia stop valves, flange ammonia stop valves. The long-term accumulated experience enables us to quickly handle and solve more technical difficulties.
