Difference between lug and wafer butterfly valves?

Butterfly valves play a very important role in controlling the flow of fluids in pipelines. Among the various types of butterfly valves, lug butterfly valves and butt type butterfly valves are widely used due to their high efficiency and ease of installation. Below is a detailed comparison of the two, highlighting the key differences between the two:

Lug Butterfly Valve

INSTALLATION MECHANISM: Lugged butterfly valves are characterised by protruding lugs around the periphery of the flange. These lugs are threaded and tapped for mounting bolts to secure the valve directly to the pipeline from both sides.

• Installation Flexibility: One of the main advantages of lug butterfly valves is the ability to disconnect from one side of the pipeline and not affect the other side. This ability is often referred to as "dead-end service" and makes maintenance and replacement easier and more efficient.

• METHOD OF OPERATION: These valves can be operated manually, hydraulically, pneumatically, or by other braking methods, and are versatile enough to meet a wide range of applications and operational needs.

• Configuration Versatility: Lug Butterfly Valves are available in a variety of configurations, depending on the number of lugs, for different sizes and specifications of pipelines.

Wafer Butterfly Valves

• Mounting Mechanism: The Butterfly Butterfly Valve design features a clamping mechanism between the pipe flanges. Long bolts run through the entire assembly and hold the valve in place by pressing the flanges together.

• SERVICE AND MAINTENANCE: Unlike lug type butterfly valves, the Button Clamp Butterfly Valve does not allow for easy disconnection on one side. To service the valve, fluid flow must be completely stopped and the piping disconnected at the flange.

• Space and Weight: Wafer-type butterfly valves are generally more compact and lighter than lug-type butterfly valves, which is an advantage in applications where space and weight are critical factors.

  
  

Essentially, the main difference between the two types of butterfly valves is installation and maintenance. A tab butterfly valve offers greater disconnect and maintenance flexibility without affecting the entire system, while a butt-lug butterfly valve is more compact but requires complete disconnection of the pipework in order to carry out maintenance. Choosing between the two depends largely on your specific operational needs and the nature of your pipework.