Minnesota Boiler License Practice Exam

Under what condition can you set the popping point of a safety valve higher than the S.W.P.?

1. The boiler is under 5 years old

2. Approved by the state boiler inspector

3. There is more than one valve, one may be 3% above S.W.P

4. There is more than one valve, one may be 6% above S.W.P.

The correct answer is: There is more than one valve, one may be 3% above S.W.P

Setting the popping point of a safety valve higher than the standard working pressure (S.W.P.) is a nuanced situation governed by safety standards. The correct answer indicates that when there is more than one safety valve on the boiler system, one of those valves can be set to pop at a pressure that is up to 3% above the S.W.P. This allowance is made because having multiple safety valves provides a system of backups; one valve can provide additional pressure relief without compromising overall safety. In situations with multiple safety valves, the rationale is that the system is more robust, and the risk is mitigated. If the primary safety valve is set to the S.W.P., the second valve can be set slightly higher, which can be beneficial in ensuring that the system continues to operate effectively without leading to premature valve activation under normal operating conditions. This flexibility is designed to maintain safety while allowing operational efficiency. The other conditions listed, such as for newer boilers or needing state inspector approval, do not address the specific provision related to multiple valves and their allowable settings above the S.W.P.