1 reply to this topic

[Yogesh Bhatt]

Dear All,

 

Is there any code/standard which mentions the safe duration for dry run of rotary lobe pumps?

The vendor catalog mentions that it is capable of running dry for a short duration of time.

I want to know the exact time.

 

Thanks in advance.

 

Yogesh

[Saml]

Yogesh, I think what you wan't to know is not knowable. It depends on the model, the service, the motor it is connected to, the operational history, the maintenance  conditions....

 

Also the failure mode my differ. Typically I would expect it to be from overheating a seizing. But may be from vibration, seal failure, etc.  And the replacement pump you will install will take shorter or longer to fail.

 

That is the reason the manufacturer is vague in the statement "a short period of time". If it fails after running dry it will be "too long", being the definition of "too long" the time needed for pump failure.

 

So, design and operate for minimum or no time running dry. Perhaps to check it is turning in the right direction or during startup until it primes, but not more.