Double expanding gate valves are made by
two sliding pieces consisting of a gate and a second segment
(male and female wedge segment). … Sealing is achieved in both high and low pressure conditions by expanding the gate and the segment out towards the seats while the wedge is in a closed position.
How does a double disc gate valve work?
Double Disc Type Gate Valves have
parallel seats against which the wedge is driven when the gate is closes
. This results in a tight seal between the disc and the seat. Variation of this design includes valves that depend on fluid pressure to force the disc against the seat.
What is expanding gate valve?
The expanding gate valve does not require line pressure to seal and is recommended when a tight mechanical seal is required. The design provides a
mechanical seal between the seats and the gate
in both high and low pressure applications. There are two piece wedged shape assembly consisting of a Gate and a Segment.
What are different types of gate valves?
Gate valves can be divided into two main types:
Parallel and wedge-shaped
. The parallel gate valves use a flat gate between two parallel seats, and a popular type is the knife gate valve designed with a sharp edge on the bottom of the gate.
Are gate valves Piggable?
Luckily, these common gate valves are
piggable
due to their through conduit design; however, it’s important to note that any valve that’s not a through conduit design will not be piggable. … One of the most common valves that are piggable is Trunnion Mounted Ball Valves, also known as Shut-Off Pigging Valves.
What is the function of gate valves?
A gate valve is generally
used to completely shut off fluid flow or, in the fully open position, provide full flow in a pipeline
. Thus it is used either in the fully closed or fully open positions. A gate valve consists of a valve body, seat and disc, a spindle, gland, and a wheel for operating the valve.
What is a resilient wedge gate valve?
FlowMaster resilient wedge gate valves are
designed to control the flow of water in fire hydrant applications
, but can also be utilized for other water distribution or sewer system applications. All valves are compliant with the Reduction of Lead in Drinking Water Act of 2011.
What is a flexible wedge gate valve?
Flexible wedge is
a one-piece disc with a cut around the perimeter to improve the ability to correct mistakes or changes in the angle between the seats
. The reduction will vary in size, shape and depth. A shallow, narrow cut gives little flexibility but retains strength.
What is a through conduit gate valve?
Through-conduit gate valves are
isolating valves designed for full closing of the working media flow
. … The gate valves are full-bore piggable valves with a flow resistance coefficient equal to that of the piping. Therefore they are suitable especially for long-distance pipeline systems.
How do you identify a gate valve?
The gate can be
shaped like a wedge, knife
, or parallel. Physically, gate valves are higher than globe valves when fully opened, but have a smaller face to face length. The gate being moved up or down is easy to visually acknowledge as the valves operate with either a rising stem or a non-rising stem.
What is the difference between isolation valve and gate valve?
An isolation valve is a valve in a fluid handling system that stops the
flow of process
media to a specific location. The Isolation gate Valve is a valve that is used to stop the flow of process media in a fluid handling system.
What are the two types of valves?
There are 2 distinct types of linear valves:
rising stem (multi-turn) and axial
. While both valve types rely on the linear motion of the flow obstructer, they are very different in construction and operation.
What does Piggable mean?
Pigging is a word used to describe
the action of cleaning a pipeline via the means of a device
, that travels through the line, known as a pig.
What is pigging in valves?
All About Pigging Valves
Pigging valves were introduced into the oil and gas industry almost 50 years ago. They are
used to introduce and retrieve pipeline cleaning and maintenance devices
. You’ll find them used in the production, storage, refining and gathering of oil or gas, water treatment, disposal and injection.
Why is it called pigging?
What are pipeline pigs? … Early pigs were made from materials such
as straw, barbed wire and leather and made a squealing sound while traveling through the pipes
– for this reason, they were eventually called “pigs”. The name eventually became an acronym for “Pipeline Inspection Gauge” or “Pipeline Intervention Gauge”.
