In many check valves, there are four holes in the body of the valve that are used to mount the hinge pin and stop pin. A retainerless design does not have any holes passing all the way through the body of the valve. In applications where very hazardous or corrosive gases are passing through the valve, a retainerless design may be preferable to minimize the chance that any gas can escape through holes in the valve body.
Check Valve with Mounting Holes
Retainerless Check Valve
When is a retainerless check valve necessary?
The amount of air that may escape from the mounting holes in the body of a check valve is miniscule. For standard air applications and even many gas applications this is of no concern. However if the gas passing through the valve is extremely toxic, hazardous or corrosive, it may be preferable to ensure you have a retainerless design.
Where can I purchase a retainerless check valve?
At pdblowers we offer both standard and retainerless check valve options. Our retainerless models are usually not kept in stock and therefore will have a longer lead time, typically 2-3 weeks. They are also generally more expensive than the standard models. Contact us with questions about inventory and lead times.