JPS5917310B2 - Gate valve actuation device for submarine wellhead - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an operating device for a gate valve used in a wellhead device of an offshore oil production system.

In the case of buried wellhead equipment, (a) all the pulp may be stored in a caisson under the seabed, so it has a particularly compact design; (b) it has high corrosion resistance (maintenance intervals are long, so it is especially durable); (3) Since it is installed from the ocean by remote control, it is particularly required to have a housing with sufficient mechanical strength.

However, conventionally, as a gate valve used in the above-mentioned buried type wellhead equipment, a gate c is connected to a simple rectangular flat spring holder a via a stem b, as shown in Fig. 1, and the spring holder a and the body are connected. By interposing a spring e between the piston h and the stem b, and applying pressure liquid from the hydraulic port g of the hydraulic cylinder f,
moves so that the hole in gate C and flow line i match, and by releasing the pressure liquid, spring e
There are gate valves designed in foreign countries that have a structure in which the spring holder a and stem b are returned by the force of , and the gate c is retracted.

There is no precedent in our country.

J is a caisson consisting of a pipe of the required size, which is buried under the seabed, and a gate valve is inserted into it.

However, in the example shown in FIG. 1, since the spring holder a is designed to be a simple rectangular flat plate, there is a possibility that the spring holder a will be damaged when inserted into the caisson j.

■ Since spring e etc. are exposed to seawater, there is a high risk of corrosion.

In particular, since this valve is always open, that is, a load is always applied to the spring, stress corrosion of the spring is likely to occur.

There are other problems.

The present invention solves the problems of the above-mentioned conventional example, and
This was done with the aim of satisfying the above requirements (a), (b), and 0→.The spring holder and cover, which is connected to the gate via the stem, is shaped like a thick bowl and slides onto the guide part of the body. The spring holder/cover is fitted movably into the body, and the space formed between the spring holder/cover and the body is characterized by having a spring interposed therein and filling the space with fluid.

Embodiments of the present invention will be described below with reference to the drawings.

The periphery of the bowl-shaped spring holder/cover 1, which has a thick wall for high strength, is slidably fitted into the guide portion 3 of the body 2 in a liquid-tight manner, and the flow line 4 provided in the body 2 is fitted to the guide portion 3 of the body 2. A stem 6 connected to a gate 5 that opens and closes the
By sending pressurized liquid to a hydraulic port 9 which is removably connected to the spring holder/cover 1 with bolts or the like and is formed by a piston 7 fixed to the stem 6 and a cylinder 8 fixed to the body 2. The gate 5 moves forward (leftward in the drawing) together with the piston 7 and stem 6 so that the hole 10 of the gate 5 and the flow line 4 are aligned.

A spring 11 is interposed between the spring holder/cover 1 and the body 2, and when the hydraulic pressure of the hydraulic port 9 is released, the elasticity of the spring 110 causes the spring holder/cover 1 and the stem 6 to close together with the gate 5.
is moved back to close the flow line 4, and the space (spring chamber) 12 formed between the spring holder and cover 1 and the body 2, which is kept liquid-tight, is filled with oil such as anti-corrosion oil. , prevent the spring 11 from being exposed to seawater.

Furthermore, a passage communicating with the space 12 is opened at the section 13 in FIG. This makes it possible to balance the inside of the space 12 with the external pressure, and also allows liquid to come in and out due to the stroke of the spring holder/cover 1.

14 is a caisson. With the above configuration, when opening the flow line 4, pressurized liquid is supplied to the hydraulic port 9 and the spring holder/cover 1 is connected to the spring 1.
This is done by moving the gate 5 forward by moving it against the pressure 1 and aligning the hole 10 of the gate 5 with the flow line 4.

When the flow line 4 is to be closed, the hydraulic pressure in the hydraulic port 9 is released, the spring holder/cover 1 and the stem 6 are pushed back by the force of the spring 11, and the gate 5 is moved backward.

When the flow line 4 is opened and closed, the space 12 in which the spring 11 is located is sealed and filled with antirust oil, so there is no risk of corrosion.

Furthermore, the pressure of the fluid filling the space 12 can be balanced with the external pressure by a pressure balancer installed in the section 13, so that it can be balanced with the ambient pressure both on the deep seabed and on the shallow seabed.

As described above, according to the device of the present invention, (1) the spring holder/cover is shaped like a thick bowl;
Since the guide part of the body can be slid, the design is compact, and there is no risk of damage even if the pulp part collides with the surroundings during remote installation, and the elasticity of the spring provides a damper effect. It is also possible to prevent damage to the enemy's island that collides with the enemy.

(11) Since the inside of the bowl-shaped spring holder and cover can be filled with fluid, it has corrosion resistance and
By providing properties such as lubricity, the spring is not exposed to seawater, and the durability of internal mechanical parts can be improved.

(iii) If the fluid filling the space inside the spring holder and cover is made to have a pressure equal to the ambient pressure using an external pressure balancer, it is possible to maintain the same ambient conditions both on the deep seabed and on the shallow seabed. can.

It can produce excellent effects such as

[Brief explanation of drawings]

FIG. 1 is a cutaway side view schematically showing a conventional device, FIG. 2 is a cutaway front view of the device of the present invention, and FIG. 3 is a cutaway side view of the device of the present invention. DESCRIPTION OF SYMBOLS 1... Spring holder and cover, 2... Body, 4... Flow line, 5... Gate, 6-... Stem, 7... Piston, 8... Hydraulic cylinder, 11
...Spring, 12...Space.

Claims (1)

[Claims] 1 Spring ho) I' connected to the gate via the stem
! - The cover is shaped like a thick bowl and is slidably fitted to the guide portion of the body, and the space formed between the spring holder and cover is interposed with a spring and filled with fluid. An actuating device for a gate valve for an undersea mine, characterized by the following.