What type of valve is commonly used for main control in dry pipe systems?

The type of valve that is commonly used for main control in dry pipe systems is a quick opening or slow-opening valve. This choice is appropriate because dry pipe systems require a specific response to changes in pressure and flow to activate the sprinkler system effectively.

Quick opening valves are designed to minimize delays in water flow when the system is activated. They allow water to rush into the pipes quickly, which is crucial in a fire situation where rapid suppression is necessary. On the other hand, slow-opening valves, while they allow for a more controlled introduction of water, are also utilized where pressure management is essential, maintaining the integrity of the system during activation.

In contrast, metered valves are typically used to restrict or measure flow rather than to control the main supply. Check valves are primarily used to prevent backflow and do not serve as main control valves. Pressure relief valves are designed to relieve excess pressure from a system, rather than control the flow of water under normal operating conditions. Thus, the use of quick opening or slow-opening valves as the main control ensures that dry pipe systems remain efficient and effective in fire suppression.