Isolation Valves

manual isolation valves

Manual isolation valves play a key part on any plant, giving satisfactory isolations to apply safety from the system. They also provide isolation to system processes for venting, filling and many other situations.

At VAS we carry out overhaul and inspections to all types of isolation valves. During a full inspection we would strip the valve down to component level and take notes of any repairs or recommendations. Where necessary some parts are replaced, or machine repaired, and the sealing faces are lapped back to a satisfactory standard. With new soft spares the valve is re-built and tested to the relevant procedures on both seat on body tests to achieve certification. 

automated isolation valves

Automated isolation valves have the added operational use by the means of an actuator which provides an option of operating the valve remotely in an instant. 


At VAS we carry out overhaul and inspection to both the valve and actuators. During a full inspection we would strip the valve down to component level and take notes of any repairs or recommendations. For Actuator overhauls, a Pneumatic Actuator would be stripped and assessed replacing all the relevant components. Electrical Actuator drive bushes would be the key inspection point for service and replacement were deemed necessary. From our inspections some components may require replacing or machine repairing, finally the sealing faces would be lapped back to a satisfactory standard. With new soft spares the valve is re-built and tested to the relevant procedures on both seat on body test. The actuator would also be mounted and with the relevant torque or limit settings inputted and stroked on completion.

check valves

Check valves primary function is to prevent back pressure within the process acting as an isolation where necessary. 


We inspect and service all types of Check valves breaking them down into components. Frictional wear and poor conditioned sealing faces are some of the important observations and repair/replacements needed for these valves. 

Our knowledge and equipment for these types of services ensures you are left with a fully trusted and operational valve.

Frequently Asked Questions

What is an Isolation Valve used for?

An isolation valve is a valve in a fluid handling system that stops the flow of process media to a given location, usually for maintenance or safety purposes. They can also be used to provide flow logic (selecting one flow path versus another), and to connect external equipment to a system.

What is a Double Block and Bleed valve?

A double block and bleed valve (DBB) is a single valve with two seating surfaces. In the closed position it provides a seal against pressure from both ends of the valve with a means of venting/bleeding the cavity between the seating surfaces.

Our Services

Safety Valves

We undertake the full overhaul inspection and testing of all Pressure Safety Relief Valves.

Control Valves

We offer a complete overhaul, test and calibration service for all your control flow needs.

Asset Support

Provided by Outage Project Support, Conditional Walkdowns, Asset Tagging & Valve Spares.