Conn. Agencies Regs. § 29-232-63
Each steam outlet from a boiler, except safety valve connections, shall be fitted with a stop valve located as close as practicable to the boiler. When such outlets are over two inch pipe size, the valve or valves used on the connections shall be of the outside-screw-and-yoke rising-spindle type so as to indicate from a distance by the position of its spindle whether it is closed or open, and the wheel may be carried either on the yoke or attached to the spindle. In the case of a single boiler and prime mover installation, the stop valve required herein may be omitted provided the prime mover throttle valve is equipped with an indicator to show whether the valve is open or closed and is designed to withstand the required hydrostatic pressure test of the boiler. When a stop valve is so located that water can accumulate, ample drains shall be provided.
The drainage shall be piped to a safe location and shall not be discharged on the top of the boiler or its setting. When boilers provided with manholes are connected to a common steam main, the steam connection from each boiler having a manhole opening shall be fitted with two stop valves having an ample free blow drain between them. The discharge of this drain shall be visible to the operator while manipulating the valves and shall be piped clear of the boiler setting. The stop valves shall consist preferably of one automatic non-return valve set next to the boiler and a second valve of the outside screw-and-yoke-type.
Conn. Agencies Regs. § 29-232-63