Valves for Powdered Concrete Accelerator

A specialist contractor in the field of sprayed concrete has played a leading role in the research and development of sprayed concrete processes, which has resulted in sprayed concrete being the proven method of concrete placement that it is today.

The company are involved with numerous concrete spraying techniques and projects including many forms of concrete repair, the strengthening of existing masonry railway arches, utilising a combination of a structural steel frame and a reinforced structural sprayed concrete cladding systems, screeding, working with 3D models and more. The company have constructed some of the UK’s most iconic buildings and structures using their concrete spraying methods and expertise.

Pinch Valves Performing better than Ball Valves

The set up that the sprayed concrete specialist has, allows them to purge the inlet line to ensure that no powder escapes to the atmosphere. They are using a Pinch Valve from AKO UK to assist with this process, and usually use a liquid accelerator. Due to the space they have available, the 25mm Pinch Valve fits perfectly within the line.

The company were predominantly using ball valves. However, due to the corrosive nature of the accelerator, they were having to replace the ball valves at regular intervals. The Pinch Valve for powdered concrete accelerator is proving to perform very well so far, and they have not yet needed to replace any rubber sleeves.

Pinch Valve used within this application:

VMC25.03XK.50G.30LX – 1″ VMC model, air operated, alu body, stainless steel BSP threaded sockets, natural rubber sleeve.

A closer look at the Concrete Spraying Application

The powdered concrete accelerator is ambient in temperature, and passing through the valves at a pressure of 5.5 BAR using compressed air. There are two Pinch Valves as pictured above – One is normally open in line, and the other is normally closed when teed off the inlet. Approximately 20-25 cycles of the valves are performed per day. Two 24VDC solenoid valves are used with the Pinch Valves – one normally open and one normally closed.

The concrete spraying specialist are currently working on a prototype system using powdered accelerator into a concrete stream that is then applied to a substrate.

The solution for corrosive media

Pinch Valves are not only extremely simple to install and operate, perform with accuracy and lightening fast opening/closing times, but are also suitable for conveying media that is aggressive, corrosive and abrasive. Concrete is a mixture of aggregates and paste. The aggregates are sand and gravel or crushed stone, which can be fairly abrasive. With a variety of different rubber sleeve materials, AKO UK have a sleeve quality that will perform well with even the toughest of media.

See our other case studies and how well are valves are performing in similar applications, involving ready-mixed concrete, and spraying cement slurry.