RU221046U1 - Ball valve for controlling the flow of working fluid transported through pipelines - Google Patents

Abstract

The utility model relates to the design of polyethylene pipelines, namely to the design of a ball valve for controlling the flow of the working medium transported through the pipelines. A ball valve contains a body, pipes, a ball, seats, ball sealing rings, a rod, rod sealing rings, a drive cover seal, and a drive cover. The housing on the right and left is connected to the pipes. Inside the body, in front of the nozzles, there are seats made in the form of spherical rings. The ball is made with a through hole and with a recess on top and is installed between the saddles. Ball O-rings are installed between the ball and the seats. The ball is connected to a rod, which is inserted into the body in such a way that one part of the rod extends out. O-rings are put on the rod. A drive cover with a seal is fixed on top of the rod. The ball, seats and stem of the ball valve are made of ultra-high molecular weight polyethylene. The technical result of using the utility model is increased reliability and increased service life. 4 salary f-ly, 1 ill., 1 p.

Description

The utility model relates to the design of polyethylene pipelines, namely to the design of a ball valve (with a floating ball) for controlling the flow of the working medium transported through pipelines.

A ball valve is a device with a spherical shut-off element - a ball, which is designed to shut off the flow of the medium. The ball has a passage hole in the center. The medium passes through the ball valve in a position where the passage is directed in the same direction as the axis of the pipeline (the valve is open). The flow of the medium is blocked when the passage hole is perpendicular to the axis of the pipeline (the valve is closed). The position of the valve is changed by turning the drive cover a quarter turn. The torque required to rotate the ball is transmitted through the rod. The seats continue to hold the ball, preventing it from moving in the direction of the fluid flow under the influence of media pressure, preventing excess pressure on the O-rings and allowing the required torque to be maintained even at maximum operating pressure.

Currently, to regulate the flow of liquid and gaseous media during the construction of polyethylene pipelines, polyethylene ball valves manufactured abroad are used. As a rule, some of the parts of these faucets are made of high-density polyethylene, some of them are made of glass-filled polypropylene, and the most important part of the faucet is the rod, the movement of which achieves regulation of the volume of liquid or gas flowing through the faucet - from polyformaldehyde, or from stainless steel, or from glass-filled polyamide, or glass-filled polypropylene.

Despite the fact that polyformaldehyde, glass-filled polyamide and glass-filled polypropylene, being structural thermoplastics, have high mechanical properties, in particular wear resistance, the rods wear out quite quickly and cannot fulfill their purpose with the original efficiency throughout the entire period of operation. In addition, if the crane is not in operation for a long time (more than 6 months), the breakaway torque greatly exceeds the design one, and when you try to turn the crane, the crane rod and/or drive cover fails, which in some cases led to a loss of tightness tap. Friction of the ball on the seats is the main cause of failure and/or leakage of ball valves, especially with a floating ball (due to uneven pressure of the ball on the seats). Therefore, a polyethylene ball valve quickly breaks down and has to be replaced, and since polyethylene ball valves are not produced in Russia, they have to be purchased abroad.

A known ball valve for pressure polypropylene pipelines contains a polypropylene body with a stem made of structural polymer material. (RU 209 435 U1, class F16K 5/06, published 03/16/2022).

A ball valve is known, containing a body made of a polymer material, as well as a stem made of brass or polysulfone. (RU 2 229 649 C1, class F16K 5/06, F16K 27/06 publ. 05/27/2004).

A ball valve is known that contains a plastic body and has a ball shell made of polyphenylsulfone resin (PPSU). (CN 204176024, class F16K 5/06 published 02/25/2015).

The main disadvantage of the above patents is the low reliability of these valves and some components, including the ball itself and the rod for controlling the ball valve; as a result, the use of these valves is limited in areas where increased safety and reliability are required.

The purpose of the utility model is to improve the ball valve for controlling the flow of the working medium transported through pipelines.

The technical result of using the utility model is increased reliability and increased service life.

The task is achieved by the fact that in a ball valve for controlling the flow of the working medium transported through pipelines, containing a body, pipes, a ball, seats, ball sealing rings, a rod, rod sealing rings, a drive cover seal, a drive cover, in which the body is on the right and on the left is connected to the nozzles, seats are installed inside the body in front of the nozzles, made in the form of spherical rings, the ball is made with a through hole and with a recess on top and is installed between the seats, ball O-rings are installed between the ball and the seats, the ball is connected to a rod, which is inserted into the body in such a way that one part of the rod comes out, the rod sealing rings are put on the rod, the drive cover with the drive cover seal is fixed on top of the rod, the ball, seats and rod of the ball valve are made of ultra-high molecular weight polyethylene; the nozzles may have connectors for purge; the body, pipes and connectors for purge the tap are made of PE-100; ball O-rings, rod O-rings, drive cover seal are made of nitrile-butadiene rubber; Ultra-high molecular weight polyethylene PE-9000 is used.

In fig. 1 shows a ball valve for controlling the flow of a working medium transported through pipelines.

Structurally, a ball valve for controlling the flow of a working medium transported through pipelines is shown in FIG. 1 contains:

1 - body;

2 – pipes;

3 - ball (ball plug);

4 - seats (ball supports);

5 - ball sealing rings;

6 - rod;

7 - rod sealing rings;

8 - drive cover seal;

9 - drive cover;

10 - connectors for purge.

Housing 1 is connected to pipes 2 on the right and left.

Inside the housing 1, in front of the nozzles 2, seats 4 are installed, made in the form of spherical rings with recesses.

Ball 3 is made with a through hole with a recess on top.

Ball 3 is installed between the seats 4 in such a way that it rests on the seats 4.

Between the ball 3 and the seats 4 there are sealing rings of the ball 5, located in the recesses of the seats 4.

Ball 3 is connected to a rod 6, which is inserted into the body 1 in such a way that one part of the rod 6 comes out, and the other part of the rod is inserted into the recess of the ball 3 and rests on it.

Rod 6 is fitted with sealing rings for rod 7.

On top of the rod 6 there is a drive cover 9 with a seal 8 put on it.

Connectors for purge 10 can be made on pipes 2.

Housing 1, pipes 2 and connectors for purge tap 10 are made of PE-100.

The sealing rings of the ball 5, the sealing rings of the rod 7, the seal of the drive cover 8 are made of nitrile-butadiene rubber.

The ball, seats and stem of the ball valve are made of ultra-high molecular weight polyethylene, for example, grade PE-9000.

The proposed utility model works as follows.

The working medium enters housing 1 from one side through pipe 2 and in the “open” position freely passes through the through hole of ball 3 and exits housing 1 through pipe 2 located on the opposite side. Moreover, in the open position of the valve, the through hole of ball 3 is aligned with the holes seats 4. When the drive cover 9 is turned 1/4 turn, the torque through the rod 6 is transmitted to the ball 3 and it also turns 1/4 turn. The valve moves to the “closed” position. Ball 3 is kept from moving from the vertical axis by saddles 4 located on both sides. When closing the valve, the internal tightness is ensured by ball 3, which under pressure moves slightly in the direction of flow, ensuring complete shutoff of the flow (since the presented device refers to a ball valve with a floating ball) and the sealing rings of the ball 5. The external tightness of the valve is ensured by the sealing rings of the rod 7.

Table 1 presents the comparative properties of glass-filled polypropylene, polyformaldehyde, glass-filled polyamide and ultra-high molecular weight polyethylene.

Table 1

Comparative properties of glass-filled polypropylene PP-SV (PP-GF), polyformaldehyde POF (POM), glass-filled polyamide PA-SV (PA-GF) and ultra-high molecular weight polyethylene (PE-UHMW)

No. Property Recipients PP-SV (PP-GF) POF (POM) PA-SV (PA-GF) UHMWPE (PE-UHMW) 1 Density kg/ ^m3 950 1400 1350 930 2 Suitable for injection molding processing Yes Yes Yes No 3 Water absorption before saturation, % 0.02 0.1 0.3 0.004 4 Friction coefficient for steel 0.4 0.3 0.4 0.05 5 Calculated shrinkage, % 1.4 1.6 0.6 0.01 6 Vicat softening point, ℃ 140 140 140 130 7 Tensile strength, MPa 50 80 100 40 8 Linear coefficient of thermal expansion 10 ^-5 10 ^-5 10 ^-5 10 ^-5 9 Elongation at break, % 15 40 6 420 10 Mass fraction of volatile substances, mg/kg 350 400 350 thirty eleven Flammability group G4 G4 G4 G4 12 Flammability group IN 1 IN 1 IN 1 IN 1 13 Smoke generating ability D 2 D3 D3 D3 14 Toxicity of combustion products T3 T3 T3 T3 15 Thermal conductivity coefficient, W/μ 0.3 0.4 0.4 0.4

From Table 1 it can be seen that water absorption and coefficient of friction on steel for ultra-high molecular weight polyethylene (PE-UHMW) are the lowest

The manufacture of ball valve elements - rod, seats and ball from ultra-high molecular weight polyethylene (UHMWPE), for example, PE-9000 brand, eliminates their deformation and leakage of the ball valve, ensures uninterrupted operation of the ball valve for a long time, which increases the reliability of its operation and increases its service life operation.

Below is an example of a specific implementation of a utility model.

Example 1.

An SDR11 32 ball valve with a stem, seats and ball made of ultra-high molecular weight polyethylene (UHMWPE), such as PE-9000, was installed on a high-pressure polyethylene gas distribution pipeline. Over the course of 2 years of operation, the characteristics of the ball valve specified in the product passport did not change. The ball valve is sealed and fully performs its function. The torque required to control the ball valve was constant and equal to that indicated in the passport - 6 Nm. In addition, if the crane was not used for a long time (more than 6 months), the breakaway torque slightly exceeded the calculated one (no more than 20%), while on a 32 mm polyethylene crane it was 7 Nm. This is due to the low friction between components made of UHMWPE and the absence of the “sticking effect” of the ball to the seats. After cutting and disassembling the ball valve, there were no visible signs of wear. The seats, stem, seals and ball remained in the same form as they were before the valve was assembled and welded. The ball, under the maximum operating pressure of the working medium, shifted slightly, increasing the pressure on the seat closest to the outlet, thereby increasing the degree of tightness. This floating ball valve design has proven its effectiveness and safety.

Claims (5)

1. A ball valve for controlling the flow of a working medium transported through pipelines, containing a body, pipes, a ball, seats, ball sealing rings, a rod, rod sealing rings, a drive cover seal, a drive cover in which the body is connected to the pipes on the right and left, inside the body, in front of the nozzles, seats are installed, made in the form of spherical rings, the ball is made with a through hole and with a recess on top and is installed between the seats, ball O-rings are installed between the ball and the seats, the ball is connected to a rod, which is inserted into the body in such a way that one part of the rod goes out, sealing rings are put on the rod, a drive cover with a seal is fixed on top of the rod, characterized in that the ball, seats and rod of the ball valve are made of ultra-high molecular weight polyethylene. 2. Ball valve according to claim 1, characterized in that the nozzles can have connectors for purge. 3. Ball valve according to claim 1, characterized in that the body, pipes and connectors for purge the valve are made of PE-100. 4. Ball valve according to claim 1, characterized in that the ball O-rings, the rod O-rings, and the drive cover seal are made of nitrile-butadiene rubber. 5. Ball valve according to claim 1, characterized in that ultra-high molecular weight polyethylene of the PE-9000 brand is used.