Contents
Page 4: Scope.
Page 5: Tools Required.
Page 6: Disassembly and Cleaning Procedure.
Pages 7-10: Installing O-Rings and Reassembly Procedure.
Page 11: Assembly of knob.
Page 12: Install Knob onto Gas switch block.
Page 13: Final installation of adapters.
Page 14: Final Results/General Installation Procedures.
Page 15: Warranty.
1A Scope:
This document provides instructions for disassembly, O-Ring replacement and reassembly of the OmniSwivel Gas Switching Block (P/N GSB-V2, GSB-R or GSB-L).
The replacement of the O-rings does not vary between GSB-V2, GSB-R or GSB-L.
For this matter the remainder of this document will refer to the Gas Switching Block as GSB.
It is recommended that the Gas Switching Block be serviced annually or every 200 dives, whichever comes first.
NOTE: Images in this SOP may differ slightly from older model GSB’s.
1.0 Scope:
This OSI GSB v2.0 assembly procedure provides instructions for assembly of the Omni Swivel Gas Switching Block (P/N GSB-V2). Within this document, the Gas Switching Block Version 2.0 will be referred to as the “GSB”
1B Before Use Checks:
All Gas Switching blocks should be checked prior to use. See Section 7 and user information provided.
Please Note:
The GSB-V2 is for divers trained in it’s use. Please read instructions before use to ensure set up is correct. Before use check the handwheel grub-screw to be tightened to the recommended torque of 20.33 Nm (15 in-lbs).
2 Tools Required:
OmniSwivel International recommends the following tools and equipment to properly service and replace the O-Rings in the Gas Switching Block (GSB). Failure to do so may result in damage to the Gas Switching Block and voiding of the manufacturer’s warranty.
1. Tools and Kit:
l 1 ea 5/8” Open end Box end wrench
l 1 ea 3/32” hex wrench (included with GSB)
l 1 ea dental pick to remove O-rings
l 1 ea Gas Switch Block O-ring kit: OK-GSB
l 1 ea OKL-GSB **highly recommended but not required**
2. Gas Switching Block O-Ring Kit - P/N OK-GSB-V2
Note: Only this kit may be used for OmniSwivel GSB service. (P/N OK-GSB) Gas Switching Block O-Ring Kit - Contents List
l 6 ea 5/8” OD O-Ring (black): Inside Block
l 1 ea 12mm x 1mm OD O-Ring (black): External Crankshaft Nut
l 1 ea 7/16” OD O-Ring (brown): Inside Crankshaft Nut
l 2 ea 1/2” OD Viton O-Ring (brown): Anti-Vibration O-Ring on adapter
l 2 ea 3/8” OD Viton O-Ring (brown): GSB to Adapter O-ring
l 1 ea 1-3/16 OD Viton O-Ring(brown)
l 1 ea Stainless Steel Ball Bearing
l 1 ea Set Screw (Hex)
3. Port Plug 3/8”-24 for pressure testing
4. Christo-Lube lubricant (MCG-111) or Tribolube 71. Note: If the Gas Switch Block is not for use with Enriched Air Nitrox (EAN) or pure O2 then standard silicone lubricant (e.g. Dow-Corning) may be used.
5. LocTite® Thread Locker Blue (P/N # 242).
3 Disassembly and Cleaning Procedure:
3.1 Using a 5/8” wrench, remove the two 9/16”-18 adapters from the Gas Switching Block by unscrewing it counterclockwise.
3.2 Using a dental pick, remove the 1/2” O-rings from the adapters. Discard O-rings.
3.3 Using a 3/32 Hex T-Handled wrench, insert the hex into the hole of the knob. Once you feel the hex of the wrench enter the hole of the hex screw, rotate the screw counter-clock-wise until the screw comes completely out.
3.3.1 Remove the knob from the crankshaft.
3.3.2 Remove the 1-3/16 O-ring from the knob and discard. (Older models might not have this O-Ring.
3.4 Using a 5/8” wrench, remove the crankshaft locking nut by unscrewing it counter clockwise.
3.4.1 Remove the crankshaft from the locking nut.
3.4.2 Remove the 12mm x 1mm O-ring from the threaded part of the locking nut and discard.
3.4.3 Remove the 7/16” O-ring from the inside of the crankshaft nut and discard.
3.4.4 Remove the shaft from the body of the Gas Switching Block.
3.4.5 Using a dental pick remove the six* 5/8” O-rings from the Gas Switching Block. Be sure to count the O-rings after removal to ensure all have been removed. Using the OKL-GSB will be very helpful to ensure all O-rings have been removed.
NOTE: Gas Switch Blocks manufactured prior to 2007 have 7 O-rings to remove. Refer to the engraving on the GSB to verify the date of manufacture. Should you have any questions, please do not hesitate to contact OmniSwivel International Directly.
3.7 Thoroughly clean male threads on the on the adapters, knob, block, camshaft, crankshaft, and crankshaft nut. We recommend a sonic cleaner with a mild cleaning detergent such as a brass cleaner. If a sonic cleaner is not available, use a soft wire brush, such as a toothbrush to clean the gas switching block parts. Do not use hard wire brushes as this could damage the surface.
4 Installing O-Rings and Reassembly Procedure:
For installation of all O-Rings, lightly lubricate each O-Ring prior to installation unless otherwise instructed. A light film of lubricant is all that is needed.
After the O-Ring is installed again apply another light film to make sure all the surface area is covered.
4.1 Lubricate and install the new 5/8” OD O-Ring inside of the gas switch block body by using the OKL-GSB. With the light on, you can easily see the O-ring locations. Using the clear shaft to align the O-rings into the grooves while using a flat hex wrench to assist the O-ring into place.
NOTE: Look through the top of the two inlet ports to ensure that the O-rings are not inside of the air chamber.
l4.1.1 Place a small amount of lubrication on the GSB Shaft, spreading evenly over the shaft surface. Do not cover the holes with lubrication.
4.1.2 Slide the shaft into the body of the GSB. Line up the crankshaft cut out of the shaft with the hole in the GSB body.
4.1.3 Place a gracious amount of lube on the crankshaft cut out of the shaft. As referenced in the above picture. Set the block aside.
4.2 Reassemble the crankshaft nut housing.
4.2.1 Place the 7/16” O-ring (#011) inside of the crankshaft nut. (Using the end of the crankshaft that holds the knob in place can useful to help guide the O-ring into place).
4.2.2 Place the 14mm x 1mm O-ring around the threads of the crankshaft nut.
4D l 4B
4.2.3 Place a thin film of lubrication on the crankshaft, then assemble the crankshaft and the crankshaft nut. (Leave about 1/8” of the shaft out of the nut)
4.3 Install the Crankshaft housing on to the GSB body.
4.3.1 Place the crankshaft with the camshaft pointing up to the top of the body of the GSB. (Make sure to keep about 1/8” of the crankshaft outside of the nut to allow the cam to pass the internal threads of the GSB body*Use photo 4F for reference*)
4.3.2 Once the cam is rested into the Crankshaft slot of the GSB Shaft, slide the nut down so it contacts the GSB Body.
4H
l4.3.3 Using only your fingers, screw the nut counter-clock-wise and slight downward pressure to assist the threads into proper alignment. Once the nut is resting flat, screw the nut clock-wise until the threads grip and are properly seated. Continue to screw the nut on to the GSB body until the screw becomes too difficult to turn by hand.
4.3.4 Visually inspect the nut to ensure that the threads are properly screwing into the block and the nut is not cross threaded.
4.3.5 After visually inspecting the nut for proper threading, use a 5/8 Hex wrench to screw the nut into the GSB body until the nut is flush with the body. Then apply 10-inch pounds of torque to the nut.
4.3.6 Press the female threaded side of the shaft into the block until it moves into number 1 position. Then set assembled block aside.
4.4 Assembly of knob.
4.4.1 Apply a drop of LocTite® Blue to the inside threads of the knob. Thread the 1st setscrew all the way through the knob until you see the point protrude through the crankshaft hole. Back the setscrew off enough to allow the crankshaft to pass through the hole.
4.4.2 Insert spring into spring hole.
NOTE: Apply a small amount of lubrication on the top of the spring to help keep the spring in place.
4.4.3 Place the 3/16 O-ring into the O-ring groove. Place a small amount of lubrication on the O-ring. (Set aside the Knob).
4.5 Install Knob onto Gas switch block.
4.5.1 Lay GSB body flat on a surface. Place a small amount of lubrication on the 1st position indent.
4.5.2 Place the ball bearing in the 1st position.
4M
4.5.3 Lay the knob onto the GSB body.
4.5.4 While applying downward pressure on the knob, secure the set screw to the crankshaft.
4.5.5 Rotate the knob from 1st position(4N) to center position (4O), to 2nd position (4P) to ensure proper movement and that the ball bearing rests into each groove.
4.5.6 Once the knob rotates as it should, tighten the 1st set screw to lock it into place.
4.5.7 Place the set screw into the knob and lock it down. Torque 20 inch pounds.
4.6 Final installation of adapters.
4.6.1 Install the 1/2” O-ring on the smaller threads of the two adapters.
4.6.2 Install the 1/2” O-ring on the larger threads of the two adapters.
4.6.3 Screw the two adapters into the inlet holes. Using a 5/8” hex wrench, tighten the two adapters using 15-inch pounds of torque.
Proceed to Stage 5.
5 Testing the Assembled Gas Switch Block:
5.1 Place the GSB in line with the low-pressure side of the 1st stage regulator hose onto 1st position. Apply the Test Plug (PL-W / 1/2”-20 Test Plug) to the female end of the outlet.
NOTE: When pressure is applied to the system a way to release the pressure is required. Place an octopus regulator on another low-pressure port of the 1st stage regulator to relieve the pressure from the system after the testing is completed.
5.2 Open the cylinder and let the system pressurize.
5.2.1 Rotate the knob to the 1st position and place the GSB in a bucket of water. Ensure that no leaks are coming from the 2nd position adapter.
5.2.2 Ensure that no leaks are coming from the knob area.
5.2.3 If no leaks are present, continue to 5.3. If there are leaks, disassemble the GSB and check to see that all O-rings are in their proper place and that no hairs or debris is on the O-ring. Reassemble and test again.
5.3 Turn off the pressure to the GSB and rotate the knob to release the pressure from the system.
5.3.1 Remove the hose and attach it to the 2nd position adapter.
5.3.2 Repeat steps in 5.2 to ensure that there are no leaks in the 2nd position air flow.
5.3.3 If no leaks are present, continue to section 5.4. If there are leaks, disassemble the GSB and check to see that all O-rings are in their proper place and that no hairs or debris is on the O-ring. Reassemble and test again.
5.4 Turn off the pressure to the GSB and rotate the knob to release the pressure from the system.
5.4.1 Remove the PL-W from the GSB.
5.4.2 Turn air flow on and rotate the knob from 1st position to 2nd position to ensure air flows without restriction and no air flow can be felt from exposed inlet adapter.