Choke Valves Australia : Valve and Flow Control Specialists distribute 2 styles of Choke Valve – The traditional Vonk and the DUX as of 2022/2023 as outlined below.
What is a choke valve?
They are a type of control valve, mostly used in oil and gas production wells. They control the flow of fluids being produced or kill the pressure from reservoir to regulate the downstream pressure flowlines. Generally, chokes allow fluid flow through a very small opening and usually contain sand particles. The rotating disc designs can also have larger openings making them very versatile. Sand volumes depending on well flows and life can at times be severe hence valves are normally designed to handle highly erosive services. Typically, oil and gas producing wells have two valves in series. One non-regulating choke valve and one regulating choke valve downstream to the non-regulating choke valve.
What common areas & applications are choke valves used?
Production well heads
Gas reinjection in the Christmas tree
Surface and sub-sea manifolds to handle mixtures of crude, gas, water, and sand in various chemical industries.
Steam injection and blowdowns and CO2 handling in various petrochemical plants and power plants.
In drilling mud and hydraulic fracturing applications for oil and gas industries.
Flowlines with very high operating pressure requirements.
Oil and gas production platforms. Cementing and acidizing lines.
Common Choke Valve Symbols
Selecting a choke valve
Choke valves should be carefully selected based on applications and various factors like size, material, trim design, etc. The variables that influence the selection of choke valves are:
Inlet and outlet velocities
Cavitation index
Pressure drop limitations
Sound pressure level
Required flow rate
Process operating conditions
Start-up conditions
Size and Schedule of connecting pipework.
Physical properties of fluid handled
There are applications when a cheap and cheerful design or alternatively what they refer to as the poor mans choke valve which is a V port ball valve with hardened trim will suffice. However in Choke valve designs and materials you get what you pay for. In the Oil and Gas sector downtime costs big dollars in lost production. In instances where other choke valves have lasted six weeks on very severe service our choke valves on the very same service have lasted well over 6 months before just a trim had to be changed out, = over 4 times longer. That equates to not only less spares, maintenance or replacement costs, but makes the cost of a good choke valve priceless factoring minimum 4 times lost production costs into the equation.
DUX Valves and DUX DRIVE (Hydraulic & Pneumatic Actuation)
Dux is based in the Netherlands, where they manufacture choke valves that operate where others fail. The Dux reputation is renowned worldwide making it the king of choke valves. Subsea or surface operation the Dux valve is an operators valve of choice. The Dux Valve operates on a similar principle of the Vonk Valve and in essence is an enhanced upgraded version. For more information on Dux use this link. Replacing any existing dated or failed valves from other manufacturers is easy. Dux Valves, have the ability to match face to face dimensions to suit the application.
VONK
Vonk choke valves for over 50 years had always been the “go to” valve where other manufacturers products were challenged in difficult severe service applications involving high pressure drops and volumes of sand or Hydrogen Sulphide (H2S). They handled these applications while maintaining class V shutoff in service where others struggled to achieve class III when new then degenerating thereafter in ongoing operation. Vonk trim design is robust and solid, easily maintained and it consists of just 4 key major parts or sections: a bean, a turning fork, a front disc and a protecting brush. The valve design is based on a rotating disc principle, which ensures optimal control and top performance proven to be effective for decades.
The original VONK manufacture was shut down some years ago, when this occurred the technology and knowledge base through long term Vonk employees was utilized to carry on production of spares and enhancing the original choke design. This operation now continues to fulfil the support role of all Vonk products worldwide. VCS supplying an approved manufacturer and distributor of Vonk spares & choke valves. Clients, with an installed base of Vonk products have found us a reliable and flexible supplier. Shell for instance has awarded the factory with a service contract to maintain and or supply spares for Vonk chokes.
Quoting the original Vonk part numbers we can supply standard product or an enhanced version through R& D and technological advances upgrading from the materials some 50 years ago to ones that can outlast those on certain severe applications (example modulating class 2500 gas LCV’s) by 5 to 12 times. Something worth considering and insignificant to the cost of a wellhead shutdown even just once.
UPDATE 2023
As of 2023 VCS offer complete valves to the original Vonk dimensions and design allowing existing users to replace in service valves hence no change of pipework or skid layout. Some examples of the main uses of Vonk Choke valves are the petrochemical industry, mining industry, oil and gas exploration on and offshore and underground gas storage. In these environments, their specific applications are for handling slurry, handling drilling fluids, fracturing, gas injection, water injection, steam injection, oil and gas production, as blow down valves, as gas lift valves or as level control valves.
Below an overseas export order for Production Chokes
Choke Valve Actuation
While quality internals and design set a good choke valve apart from all others you need an Actuator that is reliable that compliments the valves operation. Both valve and actuator go hand in hand in quality and reliability and simplicity. There is little point in having one and not the other unless of course its hand operated. At VCS we offer Pneumatic, Hydraulic and Electric actuation to suit each unique application.
Who uses our Choke Valves? ExxonMobil, Shell, Chevron, Origin, Total Energies Conoco Phillips ENI Linde and Petronas.