Val-matic is a market leader in the design and manufacture of valves for water/waste water in commercial, industrial, and municipal applications. One of their well-known products is their range of Plug Valves. This article will discuss the benefits of the Eccentric technology which their Plug Valves utilise.


Why The Eccentric Plug Valve?

The eccentric plug valve is installed in thousands of water and wastewater, severe service and solids handling applications of slurries and sewage around the world.  Unlike the alternative multi-turn knife or gate valve, the plug valve has a ¼ turn operation which offers low cost, low torque actuation, throttling capability and positive shut-off.  Both the shaft and gearing are removed from the flow and protected from the media. The plug’s eccentric action rotates the plug in and out of the seat without scraping or binding and the linear flow path prevents clogging with minimal head loss.  The combination of the eccentric action on the seat assures a long life with minimal maintenance.

Why The Val-Matic ‘Cam-Centric’ Plug Valve?

The Val-Matic plug valve is the product of choice for many Water Authorities and Contractors for the enhanced and improved traditional and exclusive features it has offered for many years.  Adjustable and replaceable Vee-Type Packing, exclusive POP (Packing Overload Protection) Shims, exclusive Teflon & Stainless Steel Thrust Bearings and permanently lubricated Stainless Steel Radial Bearings are fitted as standard.  The ‘Cam-Centric’ bearing package is also isolated by the exclusive ‘Grit-Guard’ seal reducing contact with the media, reducing wear and extending life of the shaft seal system.

The design of the shaft seal system is such that any minimal maintenance can be carried out on the shaft seal without the removal of the actuator including removal and replacement of shims and packing.  It has also been designed to prevent over tightening of the gland follower and Vee-Type Packing which in addition to wear is a common cause of shaft leaks.  The POP Shims prevent the packing from being over tightened and can be easily adjusted by removing the shims using the pull-tab feature.

The resilient faced plug has been designed with leading industry experts to assure a tight seal and long life whilst the mating seat of robotically welded 99% pure Nickel is applied directly to the machined surface of the valve body.

The Cam-Centric plug valve range offers sizes up to 72” in diameter and can be supplied to ANSI or PN16 flange standards.  Port areas are 100% up to 4” and optional from 6” up to 36”.  For valves above 6” standard port areas are larger than many other rectangular ported valves.  This provides maximum flow characteristics with minimum head loss whilst offering simple yet positive On/Off control but also far improved Flow Control over traditional butterfly valves for Water, Solids Bearing Flow and even Air.

Stainless steel fastenings and Water Industry Approved Fusion Bonded Epoxy painting internally and externally supplied as standard for the UK, notably increases the longevity of the ‘Cam-Centric’ plug valve.   Further proof of design testing is as per the rigorous testing requirements of ANSI/AWWA C504 and third party witnessed test reports are available from the factory.

The C504 standard was originally written for a rubber seated butterfly valve for use in raw or potable water applications.  It was not written for plug valves nor was it written for untreated waste water applications, a service to which plug valves are regularly subjected.  The Val-Matic ‘Cam-Centric’ Plug Valve not only meets this standard but exceeds them and as a result offers a high quality, cost effective solution for any associated application.