1 Overview
The function of the manual pressure reducing and overflow valve in the ground blowout preventer control device is to reduce the high pressure oil (21Mpa) in the accumulator to the lower pressure required to control the blowout preventer (usually 10.5Mpa). In addition, under certain working conditions, the valve also has the function of automatic overflow and pressure reduction, so the method has two functions: oil tines and overflow.
2. Main technical parameters
Model:JYS21-25
Nominal Pressure (MPa):21
Nominal Diameter (mm):25
Flow(L/Min):160
Jobs Pressure( Mpa):0~21
Adjustment Range (Mpa):0~14
Weught:22KG
Volume (cm³):21.8*13.8*48
3. Structure
As shown in the figure, the pressure relief valve is mainly composed of the following parts:
Handwheel, locking handle, adjusting screw, spring adjusting cover, spring guide plate, large spring, small spring, connecting rod, guide sleeve, valve body, sealing box, oil inlet flange, pressure relief sealing ring, spring, drain Oil seal ring, wave spring, oil inlet plunger, lower plug, oil outlet flange.
The sealing box is equipped with a pressure reducing sealing ring and an oil drain sealing ring. There is a spring between the decompression sealing rings, and a wave spring is installed between the oil drain sealing rings. Each sealing ring contacts the oil inlet plunger to form an annular flat sealing belt. The oil inlet plunger is provided with an oil inlet and an oil outlet, and a pressure oil outlet after decompression is provided above the valve body. The outlet pressure adjustment after decompression is achieved by rotating the handwheel to compress the large spring and the small spring. When adjusting the pressure, the handwheel rotates clockwise as a compression spring, and the compression of the spring increases. The outlet pressure rises. Conversely, the outlet pressure decreases. After the outlet pressure is adjusted, lock the skipping screw with the lock handle.
4. Working principle
As shown in the figure, the pressure oil P1 entering from the oil inlet passes through the throttle K (the gap formed between the oil inlet on the oil inlet plunger and the pressure reducing seal ring) to decompress to P2 and enter the valve cavity. At this time, the oil outlet does not open. Under the action of hydraulic pressure, the sealing box moves up to seal the oil inlet and the drain port, and maintains the pressure in the valve cavity after decompression is P2. The sealing box is under the spring force and hydraulic pressure. Under the action, in a state of equilibrium.
Once the oil outlet is opened, due to the hydraulic power generated by the flow of the liquid, the sealed box moves down (the spring is extended and the spring force is reduced), and the adjusted orifice K reappears. The pressure oil is continuously discharged from the oil outlet after decompression. At this time, the sealed box is in a new balance under the reduced spring force, hydraulic pressure and hydraulic power.
If the oil outlet is closed, the hydraulic power disappears, the sealing box loses balance and moves upward to seal the oil inlet and drain. The spring returns to its original compression, so that the sealed box reaches its original equilibrium state.
Due to the increase in pressure at the oil outlet, the pressure in the valve cavity also increases, destroying the balance of the sealed box. The sealed box is moved up to open the original closed drain port to overflow. After causing the pressure oil in the valve cavity to reach the original decompression value, the drain port is closed and the sealed box returns to the original equilibrium state. This is the situation when the Annular BOP is closed and the drill tool needs to be lifted and passed through the drill pipe joint.
When the drill pipe joint enters the sealing rubber core of the awakening blowout preventer, the drill pipe joint larger than the diameter of the drill pipe squeezes the rubber core, and the rubber core is forced to move down by the piston, and the inlet rigid volume decreases, which makes the pressure relief valve When the outlet pressure rises, the seal box moves up, so that the drain port opens and overflows until the outlet pressure is restored to the original setting, so as to protect the sealant core of the annular blowout preventer from damage.
When the drill pipe joint passes through the rubber core of the annular blowout preventer, the diameter of the drill pipe joint is larger than the diameter of the drill pipe, which causes the drill pipe joint to squeeze the rubber core outward, causing the pressure at the outlet of the relief valve to increase. . However, as long as the pressure increases, the original balance with the spring force will be destroyed, and the seal box will be lifted up. As a result, the drain seal ring at the lower part of the seal box and the drain port on the oil inlet plunger appear. Crescent-shaped gap. At this time, part of the pressure oil in the valve cavity will overflow from this gap and return to the oil tank, thereby reducing the outlet pressure of the valve. Until it is balanced with the set spring force again, and the sealed box moves downwards, the crescent-shaped gap disappears and the overflow stops. In this way, the outlet pressure of the valve can always be maintained at the set value, so as to protect the sealant core of the annular blowout preventer from damage.
The functions of the spring and the wave spring are: one is to ensure the seal, and the other is that when the sealing surface of the decompression sealing ring or the drain sealing ring is worn, it can realize self-compensation to maintain the normal sealing effect.
5. Features and instructions
In the process of pressure regulation, the pressure rises in a stepped manner, but it is more stable when the pressure is reduced.
When leaving the factory, the outlet pressure of the pressure reducing and overflow valve is adjusted to 10.5Mpa. If the user needs a lower pressure, he can turn the handwheel 1 counterclockwise to reduce the outlet pressure.
In the system, the oil inlet of the pressure relief valve is equipped with an oil filter. Please pay attention to cleaning the oil filter to prevent dirt from entering the valve and hindering the normal operation of the valve.
When the oil pressure at the oil inlet of the valve changes, the outlet pressure of the valve is not affected.
Company Information
UPET OILFIELD EQUIPMENTS CO.,LTD is one of the most well-known suppliers for the oilfield equipments in China, was established in 2000, and now has grown up to a star company which is not big but very strong in this field with our persistant effort step by step in the past years.Our products refer to the whole areas of oilfields, from a very small spare part to a very big complete rig system. Our main products are: pump spare parts, mud pumps&packages, DC/AC Motors, solid control equipments, power units, truck-mounted rigs, workover rigs, land rigs, drilling pipes and drilling tools etc. All of our products are manufactured according to the API Standard, and we are authorized to use API monogram.
Our products have been exported to 15 countries& areas around the world, 80% of our exsisting customers have done the business with us by more than 5 times, no one-off customer. We will continue to expand our range, and win more customers' trust with our better and better performance.
We welcome the win-win cooperation relationship with the partners from any places in the world, each customer is our god and helper. Warmly welcome you to come to China and visit us!
With us, you will save money, time, trouble, and most important point is that you can sleep better.
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