We often hear pinned and unsold butterfly valves in the purchase of butterfly valves. For technical reasons, a pin-free butterfly valve is usually more expensive than a pinned butterfly valve. This has caused many customers to have questions: Is it better to have a pinless butterfly valve than a pinned butterfly valve?
From the appearance point of view, the most essential difference between a pin butterfly valve and a pinless butterfly valve is: whether there is a taper pin positioning on the valve plate. The way in which the pin penetrates the valve plate and the valve stem is a pinned butterfly valve, and vice versa is a pinless butterfly valve. For both pinned and pinless butterfly valves, they have advantages and disadvantages. The specific situation is as follows:
Appearance contrast - there is a clear pin head protrusion on the appearance of the pin butterfly valve, and it is not as smooth and beautiful as the pin-free butterfly valve. However, this actually does not have a particularly large impact on the overall appearance.
Process Comparison - The structural processing of a pinned butterfly valve is relatively simple. However, it needs to be repaired after a long time of use, which is troublesome when disassembling the stem and the valve disc. Because the pin that is usually hit is piled up and pressed hard by the press, it is not easy to remove the stem. The non-pinning butterfly valve is relatively complicated in the structure process because of the way of transmitting torque, but the later maintenance and disassembly is more convenient. It is easy to repair.
Stability comparison - the pin butterfly valve is fixed because of the pin, so the stability is definitely better than the no-pin structure. The no-pin structure wears out due to the wear of the mating surface of the valve stem and the disc after long-term operation. Therefore, the quality of the unsold butterfly valve produced by manufacturers without mature processing technology and equipment is more worrying. This point is also to remind customers that if you have the need for a pinless butterfly valve, you must choose a manufacturer with good qualifications and mature production experience. After all, the valve has been in the valve manufacturing industry for 25 years, and it will be more professional in terms of quality, craftsmanship and management.
Comparison of sealing performance - Finally, let's take a look at the comparison of sealing effects. There is a saying that in the actual use of the butterfly valve, there may be a situation where the medium penetrates from the place where the pin is driven to between the valve disc and the valve stem. The potential danger of this is that after a long period of time, the pin is corroded and fractured, causing the valve to fail to work, or the ram leaking or leaking inside the pipe. However, many manufacturers have begun to notice this problem. For example, the technicians of the Bundor company will weld a layer on the pin head to prevent leakage from the pin when the pin is pinned on the valve disc and the stem.
To sum up, objectively speaking, each design has its own characteristic advantages, and it cannot be said simply which is better. We only need to choose the products that are most suitable for our cost budget and working conditions, which is a good product for us.