Aleksin Plant of Heavy Industrial Valves - Tyazhpromarmatura
Home page E-mail Site map For print Home page

Pipeline valves for oil pipelines

Conference held by "Oil and Gas Systems"
complex support of oil and gas industry.
Moscow. Expocenter. "NEFTEGAS-2004".
July, 24th,2004.

 

Today our plant manufactures slide gate valves DN 350, 500, 700, 800, 1000, 1200 PN 8.0; 10.0 MPa with electric actuators.

These products are used as shut-off devices for close the flow of working medium in main oil pipelines, process flowsheets of pumping stations and tank farms with working medium temperature from -5 up to +80 C.

Total output of slide gate valves in 2003 numbered over 250 pieces, of gate valves DN 1000 mm 132 pieces.

In 2004 for the present moment we have already supplied more than 170 slide gate valves of different types and sizes including gate valves DN 1200 mm.

As you know, they used to apply wedge gate valves for oil pipelines. But this kind of valves had some serious disadvantages which were caused by their industrial design.

It was a clear understanding that the problem could be solved only by switching to other kind of valves, so in 1997 the administration of our plant made a decision to start development of a new type of valves slide gate valves DN 350-1200 mm.

Designing of slide gate valves was carried out by Design Engineering Administration of our plant.

I would like to point out briefly our Design Engineering Administration of PJSC Tyazhpromarmatura".

The Administration consists of the following subdivisions:

  • Ball valve department
  • Gate valve department
  • Computer aided design and reliability bureau
  • Technical documentation bureau
  • Pilot site

Total employment of the Administration is 55 engineers including 52 engineers with higher technical education. Mean age of the personnel is 40 years.

Computers and software are widely used during designing and development of new products. Pilot production allows to master products of high quality in the shortest periods of time.

Back to the history of slide gate valves at our plant, I`d like to repeat myself and say that the main reason was a desire to create valves free of industrial disadvantages typical for wedge gate valves, modern valves with better consumer properties.

As it is known wedge gate valves have following disadvantages:

  • Impossibility to clean cavity under wedge from mechanical depositions without valve disassembling which leads to loss of leak-proofness;
  • Risk to break parts of diagnostic gears;
  • Impossibility to use soft sealing which reduces gate valves tightness and consistency;
  • Necessity to adjust the wedge to the body and impossibility to use them separately, which complicates repair of wedge gate valves;
  • High hydraulic resistance.

The design of slide gate valves has no such disadvantages.

In 1997, according to technical requirements for slide gate valves approved in September 1996 by vice-president of SC "Transneft" Dzhardzhimanov A.S., our plant started to develop engineering documentation and to master production of slide gate valves and it was carried out in the following time-frame:

DN

Development of engineering documentation

Production and testing of pilot model

Acceptance tests

Qualification tests

Certification tests

350

April 1997

December 1997

April 1998

June 1998

February 2003

500

December 1997

June 1998

 

June 1998

 

700

July 1998

December 1999

March 2000

 

March 2000

800

June 2003

December 2003

 

December 2003

 

1000

March 2000

July 2002

 

July 2002

 

1200

May 2003

November 2003

 

November 2003

 

In addition, in September 2003 the gate valve DN 350 was specially tested for fire resistance in test laboratory "Nefttest". The results of the tests were positive.

Pilot models of slide gate valves DN 500, 700 were forwarded for operation under control and installed:

DN 700 329 km of oil pipeline Gorky-Ryazan (installed in March 2000)
DN 500 collector of oil pipeline Tujmazy-Omsk-Novosibirsk on the pump`s suction in 1999.

There are no claims on operation of the pilot models.

 

Slide gate valves have following main parts and units:

  1. Body with closure inside.
  2. Bonnet with rubber O-rings which ensure tightness of bonnet-body connection.
  3. Slide gate which shuts working medium flow in the closure.
  4. Movable seats which ensure leak-proofness of the closure member.
  5. Stem which ensures slide gate moving.
  6. Gland unit which ensures leak-proofness of stem connection against environment.
  7. Yoke unit which transforms turning movements of the control actuator into translation motions of the stem and slide gate.
  8. Column which ensures value of stem travel necessary for shutting the closure by slide gate.
  9. Electric actuator which controls the gate valve.
  10. Drain pipeline which removes testing medium as well as solid impurities of the working medium out of the cavity under slide gate.

In accordance with engineering documentation following electric actuators are possible to use to control slide gate valves:

  • EPC (made by "TOMZEL", Tomsk)
  • Evimta (made by ARM-GARANT, Ufa)

The following gate valves are completed with the following electric actuators:

  • DN 350, 500 EPC 400018 1; Evimta 13.2 1;
  • DN 700 - EPC 400018 1; Evimta 13.2 1;
  • DN 800, 1000 - EPC 100006 1; Evimta 11.2 1;
  • DN 1200 - EPC 100006 1.

According to the requirements of the customer the slide gate valves are possible to produce for electric actuator "AUMA" (Germany) and "ROTORK" (Great Britain).

 

Principle of operation of slide gate valve

After electric signal for opening or for shutting is transmitted from the control board, the turning of output shaft of electric actuator is conveyed to clutch bushing of the valve, after that it transforms into translation motion of the stem by means of thread bushing. The slide gate, connected with the stem, moves by guide bars of the body and opens or shuts bore section of the valve.

The slide gate valve is controlled by electric actuator with manual override.

Electric actuator should be completed with two-way coupling of torque limiting which ensures disconnection of the electric actuator in case if torques for opening and for shutting exceed the values specified in the certificate.

Limit switches of electric actuator should be adjustable to limit the closure travel when it is in a limit position.

The limit positions of the closure ("Open", "Shut") are determined by matching the enclosure indicator with grooves of the rode screwed into the stem.


Advantages of slide gate valves

  1. Good and long-term closure leak-proofness is achieved due to sealing made by means of movable seats with soft polyurethane rings. Sealing seats are pressed to the slide gate by means of special springs and pressure of working medium. Such design ensures required valve leak-proofness in pressure range from 0,1 MPa up to 1,1 PN
  2. As there are no "pockets" with local resistance (like in structure of wedge gate valves) and the bore of the slide gate valve together with window space of the slide gate has a shape of regular pipe, hydraulic resistance factor of slide gate valves (0,1) is equal to the pipeline resistance and does not affect the flow characteristics of the pipeline. The hydraulic resistance factor of wedge gate valves is 0,20,4.
  3. Probability of gate jamming in the body under temperature differential is minimized to zero;
  4. Due to low hydraulic resistance factor the body wear is small and service life is longer than service life of wedge gate valves.
  5. Availability of bronze backup rings bearing the main load exerted on the slide from the media flow helps to extend the service life of sealing polyurethane O-rings in the movable seats;
  6. Availability of "soft" sealing reduces risk of scoring on the closure sealing in comparison with sealing "metal-to-metal" of wedge gate valves therefore service life of the product is extended without tightness loss in the closure.
  7. Availability of drainage pipeline allows to blow out the under slide space in the lower body part and to prevent any transporting contaminations to collect there.

 

,

Back

© 2004-2017 JSC "Tyazhpromarmatura"