What is Gate Valve?
A gate valve can be defined as a type of valve that used a gate or
wedge type disk and the disk moves perpendicular to flow to start
or stop the fluid flow in piping.
A gate valve is the most common type of valve used in any process
plant. It is a linear motion valve used to start or stop fluid
flow. In service, these valves are either in a fully open or fully
closed position.
When the gate valve is fully open, the disk of a gate valve is
completely removed from the flow. Therefore virtually no resistance
to flow. Due to this very little pressure drops when fluid passes
through a gate valve.
To achieve proper sealing, when the valve is fully closed, 360°
surface contact is required between disk and seats.
Gate valves should not be used for regulation or throttling of flow
because accurate control is not possible.
The high velocity of the flow in the partially open valve may cause
erosion of the disc and seating surfaces and also creates vibration
and noise.
Valve Type | CS / SS GATE VALVE - FL / BW |
Design Std | BS EN ISO 10434 [BS 1414] / API 600 / API 602 / API 603/ASME B16.34 |
Size Range | 40 DN to 400 DN [1 1/2” to 16”] |
Body | [CS - ASTM A 216 Gr. WCB] [SS - ASTM A 351 Gr.CF8 / CF8M] |
Trim | AISI 410 / 304 / 316 |
Seat / Wedge | 13% Cr. Steel / AISI 410 / 304 / 316 |
Design Features | Bolted Bonnet, OS & YT, HW & Gear operated |
Prorating | ASME - Class 150 / 300 / 600 |
Face to Face | ASME B 16.10 / EN 558 -1 / API 6D |
End Connection | Flanged | ASME B16.5, CLASS 150 / 300 / 600 |
Butt weld | ASME B16.25 |
Testing Std. | BS EN 12266 - 1 [BS 6755-1] / API 598 |
Optional | Lantern Ring / indicator & Locking Device/ Renewable Seat /
Stellite Hard facing / Jacketed Provision / RTJ Flanges / By Pass
Arrangement / Higher Sizes / Special MOC: Austenitic and Duplex
Stainless Steels |
PN | DN | Size(mm) |
L | D | D1 | D2 | B | N-φ | H |
1.6MPa | 25 | 160 | 115 | 85 | 65 | 14 | 4-14 | 275 |
32 | 180 | 135 | 100 | 78 | 16 | 4-18 | 280 |
40 | 200 | 145 | 110 | 85 | 16 | 4-18 | 330 |
50 | 230 | 160 | 125 | 100 | 16 | 4-18 | 350 |
65 | 290 | 180 | 145 | 120 | 18 | 4-18 | 370 |
80 | 310 | 195 | 160 | 135 | 20 | 8-18 | 400 |
100 | 350 | 215 | 180 | 155 | 20 | 8-18 | 415 |
125 | 400 | 245 | 210 | 185 | 22 | 8-18 | 460 |
150 | 480 | 280 | 240 | 210 | 24 | 8-23 | 510 |
200 | 550 | 335 | 295 | 265 | 26 | 12-23 | 710 |
250 | 650 | 405 | 355 | 320 | 30 | 12-25 | 786 |
300 | 750 | 460 | 410 | 375 | 30 | 12-25 | 925 |
Types of Gate Valves
There are three ways to classify the gate valve.
Types of Disk
Solid taper wedge
Flexible wedge
Split wedge or Parallel disks Valve
Types of Body Bonnet Joint
Screwed Bonnet
Bolted-Bonnet
Welded-Bonnet
Pressure-Seal Bonnet
Types of Stem movement
Rising Stem or OS & Y Type (Outside Stem and Screw Type)
Non-rising Stem type
Features:
● Flat-bottomed seat traditional gate valves are usually deposited
in the bottom groove of the valve due to external objects
such as stone, wood, cement, paper, debris, etc., after flushing
the pipe with water. Cause cannot close tightly and form slack
phenomenon, soft-sealing gate valve using the same as the pipe at
the bottom of the flat design, not easy to cause debris deposition,
the fluid flow unimpeded, the whole package glue valve plate is
made of high quality rubber, within the whole outsourcing, domestic
first-class rubber vulcanization technology make the valve plate
after vulcanization can ensure accurate geometry size, and rubber
and nodular cast iron gate connecting firm, not easy to fall off
and elastic memory preferred.
● The corrosion resistant valve body is painted with powder and
epoxy resin to prevent corrosion and rust of the valve body, and
can
be used in sewage system.
● Not easily broken into traditional cast iron.
Types of gate valve based on body, bonnet connection
1st is screwed bonnet: This is the simplest design available and it is used for
inexpensive valves.
2nd is bolted-bonnet: This is the most popular design and used in a large number of gate
valves. This requires a gasket to seal the joint between the body
and bonnet.
3rd is Welded-Bonnet: This is a popular design where disassembly is not required. They
are lighter in weight than their bolted-bonnet counterparts.
4th one is Pressure-Seal Bonnet: This type is used extensively for high-pressure high-temperature
applications. The higher the body cavity pressure, the greater the
force on the gasket in a pressure -seal valve.
OS & Y Gate Valve or Rising Stem (Outside Stem and Screw Type)
Non-rising Stem Gate Valve or Insider Screw Valve
