(1) Sewing machine. Each sewing machine must be equipped with a guard permanently attached to the machine, so that the operator's fingers cannot pass under the needle. It must be of such form that the needle can be conveniently threaded without removing the guard. This requirement will not apply to domestic-type sewing machines having a presser-foot which is in the "down" position during operation of the machine.

(2) Exhaust or ventilating fans. Each exhaust or ventilating fan within seven feet of the floor or working platform must be completely covered with wire mesh of not less than No. 16 gauge, and with openings that will reject a ball one-half inch in diameter.

(3) Steam pipes.

(a) All steam pipes that are within seven feet of the floor or working platform, and with which the worker may come into contact, must be insulated or covered with a heat-resistive material or must be guarded to prevent direct contact with the worker.

(b) Where pressure-reducing valves are used, one or more relief or safety valves must be provided on the low-pressure side of the reducing valve, in case the piping or equipment on the low-pressure side does not meet the requirements for full initial pressure. The relief or safety valve must be located adjacent to, or as close as possible to, the reducing valve. Relief and safety valves vented to the atmosphere must be so constructed as to prevent injury or damage caused by fluid escaping from relief or safety valves. The vents must be of ample size and as short and direct as possible. The combined discharge capacity of the relief valves must be such that the pressure rating of the lower-pressure piping and equipment will not be exceeded if the reducing valve sticks or fails to open.