S&K offers nuclear check valves that prevent backflow in steam, air or water lines. They can be used in auxillaries to nuclear reactors. Where reverse flow is desired, the valves can be configured to remain open until closed by a cylinder actuator on signal. S&K nuclear valves are designed to give minimum pressure loss consistent with the type of conditions.

PBM has been approved by ASME (American Society of Mechanical Engineers) to supply nuclear rated ball valves to the industry. These nuclear valves are both "N" and "NPT" Stamp certified. PBM nuclear valves are manufactured, tested, and certified in strict accordance with ASME Section III, Class 2 or 3.

Crispin Valve manufactures air release valves for clean water and sewage, check valves, and nuclear and custom valves. Their air release valves meet or exceed ANSI/AWWA C512 standards. Their check valves are ANSI/AWWA C508 compliant.