Pump outlet safety valve

Design a safety valve for a centrifugal pump? There’s no need, right!

I also think it’s unnecessary to install a safety valve on centrifugal pumps; safety valves are generally installed at the outlet of positive-displacement pumps. I hope experts can confirm this!

There is no need for such a setup, but a return line must be installed at the pump outlet; otherwise, the pump is prone to cavitation and severe vibration. I use a mechanical three-way valve, the one shown in my image – it allows multiple functions with a single valve. I am quite familiar with this type of application, and any questions can be addressed promptly

It is generally not set up, but it may be in special cases. For example, the maximum shut-off pressure of a centrifugal pump may not fall within the design pressure of the system. If no safety valve is installed, the design pressure of the downstream system will have to be increased by one level, which results in higher costs. To reduce expenses while still meeting the process requirements, a safety valve can be installed at the pump’s outlet in such cases.

Generally, it is not necessary to install a safety valve at the outlet of a centrifugal pump, unless there are special circumstances on the part of the owner.

Actual work and production experience: 1. The centrifugal pump is not equipped with a safety valve； 2. Some centrifugal pumps are equipped with return pipes at their outlets ； 3. A safety valve must be installed on the metering pump. I would appreciate some guidance from an expert.

Actual work and production experience: 1. The centrifugal pump is not equipped with a safety valve； 2. Some centrifugal pumps are equipped with return pipes at their outlets ； 3. A safety valve must be installed on the metering pump. I would appreciate some guidance from an expert.

I’ve never seen a centrifugal pump equipped with a safety valve

Reply 1# kang*aobao: Generally, the pipes and equipment connected to the outlet of a centrifugal pump should be designed for the pump’s maximum shut-off pressure, and there is no need to install a safety valve. The safety valve is installed here primarily to protect the pump, serving as a final line of defense: when all the outlet control valves of the pump are closed, and if the minimum return line becomes blocked or fails to function for some other reason, then, if the pump continues to operate, the safety valve will activate quickly, thereby acting as a minimum return valve.

Centrifugal pumps all have a closed-pressure value, which is the maximum pressure when the outlet valve is fully closed. Before starting a centrifugal pump, the outlet valve must be closed; it can be slowly opened only once the pressure rises to near the closing pressure. Generally, the closing pressure of a centrifugal pump is not much higher than its rated pressure. The latest industrial pipeline standard GB/T 20801.3-2006 stipulates that the design pressure of the outlet pipeline for centrifugal pumps should be no less than the pump’s shut-off pressure. The same requirement is also specified in ISO 15649:2001. In fact, installing a safety valve on the outlet of a centrifugal pump can backfire; you don’t know what the appropriate setting for the pressure at which it activates should be, or rather, no setting you choose will be appropriate. If a positive-displacement pump is used, a safety valve must be installed. Due to the inherent characteristics of positive displacement pumps, when the pump outlet valve is closed, the operating pressure of the pump theoretically rises indefinitely, thereby damaging the pump body. Both domestic and international standards specify that positive displacement pumps must be equipped with safety valves