Bui. 1136, U. S. Dept. of Agriculture. 
Plate II 
Fig. I. — A Piston Type of Balanced Reducing Valve Especially 
Adapted to Service in which the Flow of Steam Is Continuous. 
The low-pressure steam acts on the piston P in the cylinder and tends to close the valve V. 
Loose weights hung on the horizontal lever counteract this tendency. The dashpot D steadies 
the motion of the piston and valve, preventing bouncing. 
Fig. 2. — A Reducing Valve Used for a Wide Range of Pressures. 
The reduced pressure operates the diaphragm A under the main adjusting spring B, thus opening 
and closmg a small pilot valve C concealed in the plug under the diaphragm. The pilot valve 
controls the admission of high-pressure steam to the space D between the two pistons E in the 
bottom of the body; this steam forces the pistons E up and so opens the main valve F. When 
the pilot valve closes, the high-pressure steam on the main valve F, the low-pressure steam on 
the larger piston, and the valve spring all act to close the main valve. 
