Underground polyethylene gas valve. Ball valves with underground installation. Diaphragm accumulator instead of accumulator
Ball valves are a type shut-off valves pipelines that are intended for gaseous and liquid media. They are used in both household and industrial conditions. Cranes have become so widespread due to their reliability, durability and simplicity of design.
Distinctive Features
Ball valves are compact, practical, neat and aesthetic appearance. They are incredibly easy to use: just turn the special handle 90 degrees. This way you can instantly stop the supply of water or gas. This factor is especially important when it comes to any accidents and leaks in gas or water pipelines.
It is also important that the tap is made of strong material, resistant to corrosion, mechanical damage and aggressive environments. In addition, the taps are wear-resistant and have a long service life. If necessary, they can be easily repaired without significant costs.
Design
The taps consist of the following elements:
- frame;
- pens;
- housing and adjusting nut;
- Teflon sealing seat;
- rod with rubber seal;
- sealing washer.
The passage of the necessary medium is carried out due to a special valve - a part in the form of a metal ball with a through cylindrical hole in the middle. The size of this hole matches the inside diameter of the attached pipe. In this regard, the valves are called full bore.
Operating the ball valve is extremely simple. If you open it completely, there will be almost no hydraulic losses in the circulation flow. This feature reduces pipe wear and increases their service life. To completely block the flow, simply turn the control knob 90 degrees.
Species
By throughput:
- full bore – 90–100%;
- partial bore – 40–50%;
- standard – 70–80%.
According to the material of manufacture:
- brass;
- plastic;
- other alloys.
Each material has certain advantages and disadvantages. The choice of a specific type depends on the purpose of the crane.
By type of fastening:
- coupling;
- flanged;
- welded;
- combined.
Scope of application
Coupling
Used to equip gas, water and heating systems residential buildings and public buildings. Most often used for standard radiators, even under carpet. Union valves convenient and easy to use, practical, compact, easy and quick to install without special equipment. Suitable for pipes with a diametrical cross-section of no more than 40 millimeters. If the pipe is larger, it is better to opt for a flanged valve.
Flanged
Mounted on pipes with a diameter of over 5 centimeters. To achieve maximum tightness, special seals are used during their installation. This type of spherical structures is characterized by increased strength indicators. They are either collapsible or non-dismountable. In the first case, the design consists of two elements (to ensure easy and quick disassembly). This is necessary in order to replace without problems faulty part designs. Non-separable flanged options have an integral body, and if any part is damaged, the valve must be completely replaced.
Welded
Most often, such ball valves are mounted in closed places and cannot be dismantled. For example, they are often used in the construction of buildings. This is the main difference welded type from everyone else. The structure is created by welding.
Combined
They imply several options for attaching to pipes. The number of branch pipes for combined valves is different; therefore, they are: through, angular, multi-way. The latter option is simply irreplaceable in situations where there is a need to simultaneously mix several different environments.
There is another, much less common type of ball valve - union valve. It is used in various industries: chemical, food, etc. Main feature Such structures are capable of repeated dismantling. They are simple to implement and easy to use.
Choice ball valve directly depends on what it will be used for and how it will be attached.
- If you need a strong and durable ball valve that is resistant to corrosion and temperature changes, then it is better to opt for a brass design. This option is ideal for hot water pipes or for the construction of underground structures.
- Plastic or polyethylene ball valve may easily become deformed or become unusable when exposed to high temperatures. Therefore, it is best used for pipes with cold water or gas.
When installing a ball valve underground, you do not need to build a special well - to adjust, you just need to remove the control mechanism and fill the assembly with soil.
To see how a ball valve works, see the following video.
For a water supply or gas pipeline, it is most convenient to embed an underground ball valve made of plastic. This design can provide a fairly long period of operation, and without any problems with maintenance.
There are many options for materials for such shut-off valves, but plastic is the most convenient, as it is not at all afraid of dampness and corrosion. We will tell you how to install it and demonstrate a thematic video in this article.
PE taps
Description
- much cheaper than metal ones, so most settlements and various industrial facilities cannot do without communication routes made of this material. In addition, the price of a PE tap is much lower than that of a steel analogue, but its service life is immeasurably longer, which also plays an important role in the choice of materials for pipelines.
- The widespread use of such a mechanism is also due to its fairly wide range of diameters.— it can be mounted on pipes with a cross-section from 20 to 315 mm and it can operate at temperatures from -20 ⁰C to +40 ⁰C, this is acceptable for any region of the Russian Federation for underground installation.
- In addition, a ball valve for underground installation can be mounted without constructing a special well for this purpose - to adjust it, it is enough to remove the control mechanism outside, and the assembly itself can be covered with earth. The distance to the ground surface from the pipe can be from 1650 mm to 2750 mm.
- The telescope rod is extended due to a square hollow profile, at the end of which a hexagonal bushing is welded, which is installed on the crane axis and rotated using a square/hexagonal metal rod.
- An underground ball valve is made from polymer materials (the design is intended for butt welding, or for). The outlet pipes on this mechanism are made of PE 100 SDR11 - this is quite enough for gas pipelines with a pressure of 10 bar and water pipelines with a pressure of 18 bar.
Note. A protective polyethylene casing made of two thin-walled pipes is installed on the extension cord.
They can move freely one into another.
Technical characteristics of some cranes
Table for SDR11
PE ball valves
| Diameter (mm) | 20 | 0,560 | 20 | 0,560 | 20 | 0,560 | 20 | 0,560 | 20 | 0,560 | 20 | 0,560 | 20 | 0,560 | 20 | 0,560 | 20 | 0,560 |
| Weight (kg) | 25 | 0,560 | 25 | 0,560 | 25 | 0,560 | 25 | 0,560 | 25 | 0,560 | 25 | 0,560 | 25 | 0,560 | 25 | 0,560 | 25 | 0,560 |
Dimensions. Standard
PE valve without purge
Installation nuances
Note. IN Russian Federation on at the moment a water or gas underground tap is not widely used.
However, a lot construction organizations show a healthy interest in such structural devices.
This shut-off valve in above-ground or underground (using wells) design can be used in gas industry. But at the same time, the instructions do not recommend using wells along the route.
The thing is that the rules for working in these tanks and recommendations for opening them significantly complicate the operation of shut-off valves of this type.
OJSC Gazprom has developed certain technical standards in which the installation of shut-off valves made of polyethylene (the price is not taken into account) is preferably carried out without wells.
Under-hatch installation
There is a standard STO GAZPROM 2-2.1-093-2006, which demonstrates (illustrates) solutions for design, construction and reconstruction polyethylene pipelines for gas lines.
The most various options installation of PE taps ball type which can be done:
- Directly on the roadway (in the middle of the road);
- Directly on the roadway (in the middle of the road) and on pedestrian sidewalks, as well as in the park area;
- Under a carpet (turf) in a park area or forest belt.
Conclusion
Do-it-yourself installation of PE taps for home plumbing is currently somewhat difficult, since there is no special equipment for this, which is supplied through a network of hardware stores.
If we talk about plastic, then for the private sector preference is given to polypropylene and at the moment this material fully satisfies the needs of private sector residents.
Underground ball valve found wide application in the field of installation of pipeline communications. It is used as a shut-off valve to shut off and regulate the flow of the working medium. Despite the simplicity of the design, it demonstrates high level reliability in operation, during its operation the presence of “stagnant” zones is excluded.
Underground cranes, presented on our website, have different purposes
- Equipping systems that transport aggressive and non-aggressive media;
- Controlled by a gearbox, but can be equipped with a pneumatic or electric drive;
- Operation under conditions of nominal pressure up to 16 MPa;
- Installation of communications in a wide range of diameters: 80-600 mm;
- Use on pipelines that are laid underground.
Design Features
The main working body underground ball valves serves as a shutter, which is a steel ball with a through hole. When the shut-off element is open, the hole and the pipeline are parallel to the same axis. When the movement is blocked, the hole moves 90° and is located perpendicular to the pipe.
For the manufacture of fittings components, alloyed and stainless steel with high anti-corrosion properties. Elastic fluoroplastic is selected for sealing.
From design features underground cranes it is worth highlighting the availability extended rod. To connect the fittings to the pipeline, welding technology is used, which provides the following advantages:
- Tightness of communication;
- Reliability of the pipeline in operation
- No maintenance required.
When using this reinforcement, you do not need to create manhole and enclosing structure. If there is a need to dismantle tap, then this is done by cutting off part of the pipes. During installation and dismantling works the shutter must be left in the open position. Otherwise, the ball may be damaged. The fittings are selected depending on the operating conditions and technical characteristics pipeline system.
You can purchase from the StroyNefteGaz company underground ball valves for various pipelines. All models presented are different high quality execution and long term operation.
For pipelines buried relative to the ground surface, an underground ball valve has been created driven by an electric motor, pneumatic cylinders, a gearbox or a T-shaped key. The body has a multi-layer anti-corrosion coating, the spindle extension is protected by a vertical shell pipe with a flange connection to the upper part of the shut-off valve body.
Design Features
Initially, the ball valve has more than 100 design options, each of which has its own marking in table No. 1 ST TsKBA 036 of 2007. For example, single-pipe 10nzh937p, coupling economy 10nzh12p, retro 10nzh11p, three-way 10nzh2p, welded 10s7p, all-metal monobody 10nzh13p, fitting 10nzh14p, reduction 10nzh24p, with leakage control 10s28p, with heating 10nzh29p, distribution 10s33p, and many other options.
Almost each of them is suitable for underground installation, but only after making special changes to the design. For example, installation inside a well and with simple backfilling with soil is possible. In the latter case, it is imperative to protect the extension cord with a tubular sheath along its entire length. The pipe is attached to the body with a flange, so a counter flange is required in the upper part.
Ball valve body
The design of the ball valve body depends on several objective factors:
- manufacturing method;
- development of design bureaus of a specific manufacturer’s plant;
- requirements of GOST, TU, OST and ST standards.
According to manufacturing technology, ball valves are divided into categories:
- in an all-metal non-separable body;
- two parts;
- of three elements.
In the first case, the body is turned on a machine, cast centrifugally into formwork, and welded from several tubular blanks or two stamped parts.
In the second version, the ball valve body is assembled on flanges from two vertical halves. In the latter case, the seat and ball are pulled together into a single package by side pipes through flanges using pins.
In addition, the body of an underground ball valve can be full bore or pressure reducing. In the first case internal diameter coincides with the cross-sectional size of the pipeline, the hydraulic resistance inside the pipeline is minimal. In the second option, the valves are narrowed by one standard size, that is, they can reduce the flow characteristics of the working medium; diagnostic and cleaning devices will not be able to pass through such a valve.
A collapsible body made of 2 or 3 parts is much more convenient from the point of view of servicing shut-off valves. At any stage of operation and during scheduled maintenance, you can clean the internal cavity or replace the seat rings. A non-separable housing is much more airtight and cheaper to produce.
Some manufacturers use original technical solutions in the design of the ball valve body. For example, drainage system in the housing of large-diameter fittings allows you to drain condensate from the pipeline transporting natural gas.
When using a hydraulic and pneumatic drive, they can be controlled from external sources and the transported medium itself. For this purpose, the housing is made special holes, and the drive is connected.
The bypass system allows you to safely equalize the pressure inside the valve cavity and behind the nozzles, which is especially important for ball valves DN 700 - 1400 mm.
The body material is carbon, alloy and stainless steel with the markings “c”, “hp” and “nzh”, respectively. Depending on the method of installing the ball valve underground, different protection of the body from aggressive environments is used:
- acrylic paint – has electrical insulating properties, protects the fittings from stray and induced currents;
- epoxy-based coal tar paint – resistant to electrical corrosion and mechanical damage;
- polyurethane foam coating - used for well-free installation directly into the ground;
- polymer paint coating– standard protection against corrosion and mechanical damage.
Large-sized ball valves for underground installations are mounted using cranes and manipulators. For hooking, fabric and cable slings are used, but additional load-bearing devices are usually not installed on the hull.
Locking unit
Initially, an underground ball valve belongs to the category of rotary valves. There are cut-off, shut-off, regulating, shut-off-reducing and regulating-cut-off modifications for specific operating conditions. The main features of ball valves are:
- movement of the spherical plug from one extreme position (“open”) to another (“closed”) during the rotation of the spindle by 90 degrees, which is why the valve is called half-turn;
- the plug is mounted in supports, a wear-resistant anti-corrosion coating is applied to its surface;
- the seats have a ring design that evenly distributes the pressure of the working medium onto the ball;
- Manufacturers provide lubricant supply to the spindle and seat assemblies.
Included in the basic package of ball valves large diameter By default, a combined drive with the ability to operate on gas or liquid media is usually included. This is the most economical option to reduce the operating budget main pipeline.
The design of the plug in the supports makes it possible to spring the seats to the spherical plug or use the pressure of the working medium itself for the same purpose. This ensures maximum class A tightness of the valve assembly on both sides of the valve. Secondary soft seals and special grooves into which the rings go are, in turn, responsible for the safety of the rings themselves.
Relieving pressure from internal cavity valve body is only possible when transporting liquid media. For gas pipelines, taps are produced with a sealed internal cavity without drainage or bypass.
The climatic design according to GOST 15150 - “UHL”, “HL”, “U” or “T” is chosen by the customer himself.
Spindle and extension
Manufacturers of underground ball valves usually provide spindle extensions in the following sizes:
- less than 1000 mm;
- 1001 – 1500 mm;
- 1501 – 2000 mm;
- 2001 – 2500 mm;
- 2501 – 3000 mm.
In this case, the lower part of the tubular shell of the spindle extension is fixed with bolts with a mating flange on the ball valve body. A T-shaped wrench (usually in fire hydrants and chemical storage systems), a pneumatic or hydraulic drive, a gearbox with a bevel, spur and worm gear, an electric drive or a hand wheel/handle is put on the upper end of the extension.
If the hydraulic pneumatic drive is controlled by the working medium from the main pipeline, copper or steel tubes tying the valve body with the nozzles of the drive device. The tubular shell of the spindle extension is covered with the same protective compounds, with which the body of the ball valve is protected - paint and varnish or polymer materials.
Drive device
For an underground ball valve, operation with all types of drives specified in the table of figures of GOST R 5272 of 2007 is allowed:
- 0 – remote control;
- 3 – 5 – mechanical gearbox with worm, cylindrical and bevel gear, respectively;
- 6 – pneumatic drive;
- 7 – hydraulic drive;
- 8 – electromagnetic solenoid;
- 9 – electric drive.
In addition, drives can be installed upon customer request combined type– electrohydraulic, pneumohydraulic. For diameters from 400 mm, AZK automatic machines are often used, closing the tap without operator intervention. For piston drives with liquid and gas working media, control units BUK, BUP and EPUU with power supply from 24 V, 110 V or 220 V DC are required.
To be used at gas facilities/mains in Moscow, a ball valve for underground installation must have a GasCert certificate. In heat supply systems, hot water supply and hot water supply, such documentation is not needed.
In addition to ball valves with all types of drives for any installation methods, our resource offers pipeline parts, shut-off, control, shut-off, emergency valves from leading brands of the Russian Federation and own production. Consultations for site visitors are absolutely free.
In the underground version, it is intended for installation on gas and water pipelines located underground, and acts as a locking mechanism.
The working environment is controlled by opening or closing the shut-off valve.
Thanks to the auxiliary bearing, the ball moves smoothly after being installed in the ground.
These taps have a full passage of the working medium passing through them. For taps with a diameter over 200 mm, a mechanical operator is installed, which reduces the torque and ensures smooth opening/closing.
The crane structure is made of plastic material(PE 100), which provides the most maximum corrosion resistance, thereby extending the service life to 50 years.
Unlike underground steel cranes, underground polyethylene cranes have a removable telescopic rod, which can vary from 1.2 m to 2.0 m.
Polyethylene ball valves can be manufactured with diameters from 20 mm to 400 mm.
The polyethylene underground valve is connected to the pipeline by butt or electric welding, and has a durable, airtight, leak-proof work environment connection.
Two (and in the case of large diameter valves, three) sealing rings installed between the bearing and the housing, especially which is located at the bottom of the bearing, uniquely increases the level of tightness.
The pin between the adapter and the bearing securely fixes the tap during opening and closing.
The sealing ring installed between the adapter and the body prevents soil and dust from entering the tap.
Polyethylene ball valves for underground installation can be installed on a gas pipeline with a pressure of no more than 10 bar, and a water supply with a pressure of no more than 16 bar, and in the temperature range from -29ºС to 60ºС.
To facilitate the rotation of the shut-off element in large-diameter taps, one-way and two-way blowdowns can be used.
Material and properties of parts:
1. Housing
Material: HDPE polyethylene – polyethylene low pressure(high density)
Characteristic: the housing is designed taking into account the installation of the ball inside, the tightness and tightness of the bearing, ball seat, retainer, and O-rings. The bottom of the housing is machined tightly for easy installation. The bearing and adapter are located in the center of the bottom. Interior housings are processed cleanly and accurately using CNC machines for reliable installation every detail.
2. Bells
Material: polyethylene(MDPE: medium density polyethylene)
Characteristic: Sockets are made to fit a specific pipe connection. Manufactured with grooves for inserting heat conductors. At the customer's choice, it is possible to install it for any type of tap (without blowing, with one, two blows).
3. Ball
Material: polypropylene (POLYPROPYLENE: PP)
Characteristic: The ball is made using a CNC machine. The ovality of the ball does not exceed 30㎛, due to which there is no damage to the seat due to friction. The applied silicone grease allows work even with minimal torque.
4. Bearing
Material: acetal (ACETAL)
Characteristic: Bearings are made from acetal parts, digitally molded from extruded blanks taking into account stability, elongation, and dimensional stability. Increased tightness thanks to 3 O-rings - between the middle of the rod and the body (2 pcs.) and between the lower part of the rod and the body (1 pc.).
5. Ball seat
Material: NBR (RUBBER)
Characteristic: Ball seat, O-ring, and other rubber parts are made of nitrile butadiene rubber (NBR) to improve elasticity, elongation, durability under standard temperature and pressure ranges.
6. Lock
Material: polypropylene (POLYPROPLENE)
Characteristic: These elastic retainers are injection molded from polypropylene and are inserted on both sides of the body and hold the ball seat firmly.
7. Adapter
Material: polypropylene(POLYPROPLENE)
Characteristic: Made of polypropylene by injection molding, taking into account the heavy load when the ball is released, including tensile force, elongation, impact resistance. There is a locking device at the bottom of the adapter that prevents rotation beyond 90°. An O-ring is inserted inside the adapter, with which it is possible to prevent the entry of foreign particles.
The adapter can withstand heavy loads.
8. Auxiliary rod
Material: acetal (ACETAL)
Characteristic: Provides simple, easy operation even when the valve is buried deep in the ground. Designed to withstand the heavy load that occurs at the bottom of the stem when the ball is released (which even exceeds the load at the top!). The lower part is made of acetal by injection molding and withstands the greatest excess torque when opening/closing the tap.
9. Mechanical operator
Material: polyethylene, etc.
Characteristic: designed for large diameter taps (over 200mm), installed on an auxiliary rod with 4 gearboxes to reduce torque. Resistant and anti-corrosion. The flywheel opens/closes easily with 2½ turns. The mechanism is equipped with a safety device to prevent unnecessary loads when opening/closing is completed ( internal parts can be replaced if they break).
