Maintenance of Thayer Valves

Maintenance of Thayer Valves

Periodically it is desirable to remove the valve sections from the bell. Disassemble and clean the valves. This can be done by merely washing out the valve case and rotor with mild soap and water. At the same time you will maintain top acoustic performance if you clean the inside of the tubing with a trombone brush under running water.

For lubrication, a film of light petroleum-based valve oil can be applied to the tip of the rotor cone and to the shaft. We have found that the valve works well with water. Simply spray water into the valve through the hand slide receiver and the tuning slide receiver on the D. Do this while operating the valve to spread the moisture. It is a good idea to apply a tiny drop of oil on the shaft where it emerges from the brass valve casing.

DISASSEMBLY INSTRUCTIONS – DOUBLE VALVE MODEL

1. Remove all three tuning slides.

D VALVE SECTION REMOVAL

2. Remove screw from the Lap Braces
  a. Between the upper D tuning slide and the bell section.
  b. Between the lower F and the lower main tuning slide.

3. Disconnect the nylon linkage from the stop arm. The nylon socket can be popped off the ball with a screw driver placed between the nylon and the stop arm.

4. Unscrew the large nut from the rear main brace.

5. The D valve section should now be easily removed by pulling rearward. It will separate at the slipjoint connection between the two valves.

6. Unscrew the small union nut joining the D tuning slide receivers.

7. With a screwdriver, pry the stop arm off the shaft.

8. Unscrew the large screw ring from the D valve case. You should now be able to separate the valve head plate from the conical valve body.

F VALVE SECTION REMOVAL

9. Remove the screw from the Lap Brace between the upper F tuning slide and the bell section.

10. Pop the nylon linkage from the stop arm ball (as #3 above).

11. Unscrew the large nut at the top of the front main brace. The F section is now free from the bell.

12. Unscrew the large screw ring from the F valve. Separate the valve head plate from the conical valve body.

After cleaning/servicing reassemble in reverse order.

 

MAINENTANCE OF THAYER VALVES

Periodically it is desirable to remove the valve section from the bell. Disassemble and clean the valves. This can be done by merely washing out the valve case and rotor with mild soap and water. At the same time you will maintain top acoustic performance if you clean the inside of the tubing with a trombone brush under running water.

For lubrication, a film of light valve oil can be applied to the tip of the rotor cone and to the shaft. We have found that the valve works well with water. Simply spray water into the valve through the hand slide receiver or main tuning slide receiver. Do this while operating the valve to spread the moisture. It is a good idea to apply a tiny drop of oil on the shaft where it emerges from the brass valve casing. Use only a petroleum-based oil.

DISASSEMBLY INSTRUCTIONS – SINGLE VALVE MODEL

1. Disconnect the nylon linkage from the valve stop arm. The nylon socket can be popped of the ball with a screwdriver placed between the nylon and the stop arm.

2. Remove both the F tuning slide and the main tuning slide.

3. Remove the lap brace screw between the bell section and the upper F tubing.

4. Unscrew the disconnect union nuts on both front and rear braces. This will free the unit for removal away from the bell.

5. Remove the screw from the end of the shaft. With a screwdriver pry the stop arm off the shaft.

6. Unscrew the large screw ring at the rim of the valve.

7. Gently pull the case head with the rotor from the valve body.

8. Remove the rotor from the case head. Clean the rotor and valve interior surfaces with soap and water.

9. Apply a small amount of Vaseline to the valve screw ring threads to avoid seizing.
Reassemble the unit in reverse order.