Ball Valve and Gun Assembly
by J.C.

The assembly procedure is as follows:

1) Drill, tap and insert the rod into the rubber ball. Put the ball in the lath and bore it to insure it is center.

2) Disassemble the MPA-7. You'll find a small hole in the piston. Insert a small rod and unscreww the piston out of the valve body. Bore and tap a 6/32 hole in the piston.

3) Screw the valve body onto the ball valve.

4) Inset the ball/rod assembly into the ball valve body

5) Drop two MPA-7 springs into the valve body or 1 slightly stiffer than the one MPA-7 spring.

6) Hold the ball tightly into 1/2" hole and screw the piston into valve body. A bit of oil on the piston rubber will help.

7) CRITICAL ADJUSTMENT: Make sure the piston is deep enough so that the brass head of the valve, when screwed in, will NOT touch the piston. Otherwise, it will push the piston/rod/ball and open it slightly causing the system to leak. If the system leaks, this is the first thing to check i.e. screw the piston down onto the rod one turn or so.