Most frequent questions and answers

A gate valve is generally used to completely shut off fluid flow or, in the fully open position, provide full flow in a pipeline

The main difference is in the operation. A gate valve moves a solid disk up and down to open/close the orifice. A ball valve rotates a ball (the orifice) with a bore in it 90 degrees to open/close the valve.

Ball valves are more effective at forming a tight seal and have more reliability and longevity than gate valves, but tend to be more expensive. They are often used for shutoff and control applications. Because ball valves can open and close immediately, they are more likely than gate valves to cause water hammer.

If you already have a gate valve installed and have to replace it, you can certainly replace it with a ball valve. You will need a torch to heat up the parts and remove them. Turn the water off and drain it from the pipe and valve. You will want to open the valve as well.

Gate valves are equipped with a wedge-shaped metal gate that can be lowered to halt water flow and raised to allow flow to continue. When the gate is fully drawn up into the valve, it retracts entirely, allowing the water to flow through without any reduction in pressure.

When pressure changes in the piping cause flow reversal, check valves protect pumps and other equipment from damage caused by backflow.

A backflow preventer is to be used in high hazard situations and is meant to fully protect the potable water with their fail safe design while a check valve is used in low hazard situations and prevents backward water flow but it does not have the same fail safe components

Check valves are one way valves, that prevent water from flowing back down a pipe after its been pumped

A choke valve is a mechanical device that induces restriction in a flow line, causing either a pressure drop or a reduction in the rate of flow

Check valve can be installed in horizontal or vertical piping runs, with the flow running upward. Mounting for vertical installations is critical

to control the flow of fluids produced from wells

Fixed choke and Adjustable choke

An adjustable choke (or variable choke) is a type of valve used in well control operations including well testing, choke manifold and well-cleaning operations. In a closed wellbore, the adjustable choke helps in reducing the pressure of a fluid from high pressure to atmospheric pressure.
Since it is adjustable i.e. can be opened and closed, it can be adjusted to closely control the pressure drop.
For well completion operations, the adjustable choke located near the Christmas tree controls the production of fluid from a well.

An adjustable choke (or variable choke) is a type of valve used in well control operations including well testing, choke manifold and well-cleaning operations.

In oil and gas production a choke manifold is used to lower the pressure from the well head. It consist of a set of high pressure valves and at least two chokes. These chokes can be fixed or adjustable or a mix of both.

The choke manifold is the necessary equipment to control well kick and implement pressure control technology for oil and gas wells. When the blowout preventer is closed, the opening and closing of the throttle valve is used to control a certain casing pressure to maintain the bottom hole pressure to always be slightly greater than the formation pressure, and to prevent the formation fluid from further flowing into the well. … When the pressure in the well rises, the throttle valve (manually adjustable, hydraulic and fixed) on the choke manifold can be opened and closed to release the fluid in the well to control the casing pressure.

The choke manifold is an important equipment for oil and gas wells, which has the function of controlling the kick and pressure control technology. When the blowout preventer is closed, a certain casing pressure is controlled by opening and closing the throttle valve, so that the bottom hole pressure is always slightly higher than the formation pressure to prevent further formation fluids from flowing into the well. In addition, when shutting in the well, the choke manifold can be used to relieve the pressure to complete the soft shut-in. When the pressure in the well rises to a certain level, it is used to protect the wellhead from blowout.

A manifold is a system of headers and branched piping that can be used to gather or distribute fluids, as desired. … Manifolds can be used to gather produced fluids and direct selected wells to a well test line, as well as to distribute injected fluids (gas or water) or gaslift gas to individual wells.

The choke and kill manifold is a special well control manifold composed of choke valves, various valves, manifolds and pressure gauges. It is used to control the discharge of annulus fluid and the back pressure of fixed wells.

In oil and gas production a choke manifold is used to lower the pressure from the well head. It consist of a set of high pressure valves and at least two chokes. These chokes can be fixed or adjustable or a mix of both.

At the surface it is connected to the drilling spool.

A wellhead is the component at the surface of an oil or gas well that provides the structural and pressure-containing interface for the drilling and production equipment.

According to the different use site, it can be divided into land, ocean platform and underwater

wellhead including Christmas tree,Christmas tree is the key component.

In order to effectively protect the oil (gas) layer, safe construction and safe production

It typically consists of a casing head, tubing head, BOP stack, four-way, bypass fitting.


It is mainly used for hanging the tubing string in the well, sealing the annular space of oil casing, controlling and regulating the production of oil well, ensuring operation, construction, taking oil, casing pressure data, testing and wax removal and other daily production management

Christmas tree is an important equipment for oil and gas exploitation, which consists of casing head, tubing head and tree

it is used to connect casing string and oil string, seal the annular space between each casing and tubing, and control the pressure of production wellhead and adjust the flow rate of oil (gas) wellhead. It can also be used for acidizing fracturing, water injection, testing and other special operations

usually it has 4-8 gate valves

A flow cross installed on top of a frac tree where treating iron is connected and treatment fluid enters the frac tree

Flanges are used to connect pipes with each other, to valves, to fittings, and to specialty items such as strainers and pressure vessels

the welding neck, long welding neck, slip-on, socket weld, lap joint, threaded and blind flanges

the standard flanges and the special ones

A ring-type gasket is placed and installed inside of the flange bolts and around the pipe bore

Different materials, different uses

An annular blowout preventer is a large valve designed to seal, control, and monitor oil and gas wells. These BOPs have elastomeric sealing, a valve resembling a large rubber donut, which mechanically squeezes inward to seal the drill string, casing, open hole, or pipe.

A ram BOP is a blowout preventer that uses a pair of steel plungers that oppose each other (rams). The rams can extend towards the wellbore’s center to restrict the flow of fluids or retract open to permit the flow.

The annular BOP helps seal the space around the drill pipe (also known as annular space) during a “kick.” But, a ram BOP is designed to seal off a well when the drill pipe, tubing, or casing is in the well.

Single RAM BOP, double RAM BOP, multiple RAM BOP

Function of pipe ram is to restrict the flow of fluid between the wellbore and outside of drill pipe.

BOPs and associated valves are installed on top of the casing head before drilling ahead after rigging up.

It means the BOP equipment includes two rams.

Usually available in cylindrical or conical shapes, plug valves are quarter-turn manual motion valves used for stopping or starting the flow of fluid.

In principle, the ball valve can also be regarded as a special plug valve. The plug valve core is cylindrical or cone-shaped, while the ball valve core is spherical.

Swivel joints are precision machined components that are used to connect and prevent bends in stationary loading hoses that can reduce flow, tear, or rip, releasing harmful chemicals into the air.

With these swivel joints, a rotary seal between the stationary and rotating parts of the manifold contains the pressurized fluid, but allows relative rotation between the two halves.

In most cases it’s best to avoid swivel joints because they are what is known as a “living joint

Pup joints are also known as saver sub, spacer and pup.

A Pup Joint is a shorter versions of tubing and casing, used to adjust the length of a string to it´s exact requirements.

Pup Joints can range anywhere from 2 feet to 25 feet.

BOPs come in two basic types, ram and annular. Both are often used together in drilling rig BOP stacks, typically with at least one annular BOP capping a stack of several ram BOPs.