SUBJECT
POSSIBLE LOOSENING OF EMERGENCY VALVE ASSEMBLY (PIN 505-018) from the "B" SIDE BLOCK ASSEMBLY BODY (PIN 550-029) on "B" side block assembly style D.S'!. Helmets and Masks.
BACKGROUND
A "B" Side Block Assembly (PIN 505-024) was found to have an Emergency Valve Assembly (PIN 505-018) on it that was not tightened fully. These loose Emergency Valve Assembly's do not leak, and cannot become disassembled from the "B" Side Block Assembly as the Control Knob will not rotate past the Helmet Shell or Mask Frame.
RECOMMENDATIONS
If the Emergency Valve Assembly on your D.S.I. Mask or Helmet is capable of being loosened by grasping the Control Knob (PIN 520-016) on the Emergency Valve Assembly and pushing it upward with minimal force, you will need to follow the instructions on the attached sheet to insure that the parts are retightened correctly. If the Valve will not unscrew after using minimal force, do not proceed any further.
CORRECTIVE ACTION
If you are able to loosen the Emergency Valve Assembly by hand, follow these procedures;
1. Remove the Locknut (PIN 550-019), Spring (PIN 535-802), and Knob (PIN 520- 016).
2. Undo the Packing Nut (PIN 550-032). When the Packing Nut is free of the threads of the Emergency Valve Body (PIN 550-036), Back out the Stem (PIN 550- 035) until it is free of the Emergency Valve Body. (Do not disassemble Packing Nut (PIN 550-032), Washer (PIN 550-034), and Stem (PIN 550-035).
3. Remove the Check Valve Assembly (505-060).
4. Try turning the Emergency Valve Body (PIN 550-036) in by hand. Then, using a 8" adjustable wrench, tighten the Emergency Valve Body (PIN 550-036) by turning it in by three turns.
5. Reassemble the valve by rotating the stem (PIN 550-035) until it is seated all the way in, then back it out about 1/2 tum.
6. Start threading the packing nut (PIN 550-032) on to the body. Run the nut in and tighten slightly with a wrench.
7. Place the knob (PIN 520-016) onto the stem.
8. Tighten the packing nut (PIN 550-032) with a wrench until some friction, or some resistance is felt when turning the knob.
9. Place the Spring (PIN 535-802) and Locknut (PIN 550-019) onto the stem (PIN 550-035), securing the Knob. Tighten the Locknut. The assembly is now complete.
10. Install the Check Valve Assembly (505-060). Tighten to 240 inch pounds of torque.
Remember that you will find additional information regarding these procedures in the manual for your respective units. If you are not confident regarding your ability to preform these procedures and would like to have D.S'! inspect your Helmet, Mask, or Spare "B" Side Block Assembly, please contact our sales department regarding this matter. We will inspect, and if necessary repair it at no cost to the ownertened fully. These loose Emergency
Valve Assembly's do not leak, and cannot become disassembled from the "B" Side
Block Assembly as the Control Knob will not rotate past the Helmet Shell or Mask
Frame.
