Pressure tank backstop valve seal not tight should do:
1、检查止回阀内外部增加弹簧、垫片等，增加密封外力。
1. Check the inner and outer of the check valve to add springs, gaskets, etc., to increase the external sealing force.
2、检查不对称的阀板，重新分散密封面的屈服应力。
2. Check the asymmetrical valve plate to re-disperse the yield stress of the sealing surface.
3、重新调整止回阀动作，减小其闭合时的通过损失。
3. Re-adjust the action of check valve to reduce the passing loss when closing.
4、使用有良好自密封性能的阀门替换止回阀。
4. Replace the check valve with a valve with good self-sealing performance.