Scubapro MK25

[ROMO DIVER]

To the OP:

While all this torque talk is fascinating and all, I will try to add something different that might be of interest. When you get the Mk25 changed to DIN (torqued or not) you might look at getting a DIN adapter to put on the yoke you pulled off. I have all my Mk25's set up as DIN for cave diving but keep the yoke adapter in my OW vest so any time I am diving AL tanks I just pull it out and slap it on. That way there is no chance of forgeting it and I am always able to dive any tank.

 

[halocline]

Torque settings for yoke clamp/din connector is 12 ftlbs for Apeks. Same as the turret retaining bolt and less than half of what the port plug and hose connections are. Hoses and plugs are 23-27 ft lbs.

The second stage specs are in the 40 lb range for their retaining nuts and hose swivel.

Something's wrong. Port plugs 27 ft lbs? I don't think so. 40 ft lbs for retaining nuts set in a plastic case? That can't be right. Are you sure those specs are not in inch/pounds?

OTOH, 12 ft lbs sounds pretty low for a yoke/DIN retainer. Scubapro is almost double that.

It doesn't surprise me that you can come pretty close just by feel, but not everyone can do that.

 

[redacted]

Something's wrong. Port plugs 27 ft lbs? I don't think so. 40 ft lbs for retaining nuts set in a plastic case? That can't be right. Are you sure those specs are not in inch/pounds?

OTOH, 12 ft lbs sounds pretty low for a yoke/DIN retainer. Scubapro is almost double that.

It doesn't surprise me that you can come pretty close just by feel, but not everyone can do that.

Yep. 27 ft-lb on a port plug is probably going to break something. And the correct units on the "40 lb" is inch-lb. Using a torque wrench to apply 12 times the spec torque is probably worse that just going by feel and staying light.

12 ft-lb on the yoke/din retainer is on the light side of what most manufacturers recommend. Scubapro spec is about twice that which is on the upper end of what you generally find - probably because of their BP design which can be affected when the rig is lifted by the 1st stage body. I believe SP blamed techs for the over torquing damage that caused the Mk20 recall but I'm not at all sure it could not have been caused by boat hands lifting rigs out of the water and into the boat.

 

[Zung]

Apeks/Aqualung specs:

• LP ports & hoses: 20 to 40 in.-lbs
• DIN/Yoke retainer: 12 to 20 ft.-lbs

Apeks generally on the lower side of the range, Aqualung on the higher side, as per the service manuals.

Messing up in. & ft. would lead to dire consequences

 

[tbone1004]

they were in inch lbs, sorry. Working on mech engineering senior design projects and everything we do is in ft. lbs. Numbers were right, wrong units. I'm not entirely sure I could put 45 ft lbs of torque on something that's not in a vice with a fairly hefty wrench. Certainly not holding a stage by hand...

Looking at the xtx DST manual now. 14.7 ft lbs for the Handwheel connector.
5.9 ft lbs for the turret retaining bolt.
Handwheel connector is different for DIN and Yoke.

Yoke instructions
Insert the Yoke Clamp Connector (35) through the Yoke Clamp (29) and the Distance Piece (8). With the Valve Body held so that the inlet connection port points down, screw the Yoke Clamp Connector into the Valve Body (7) until finger tight.
Secure the Valve Body (7) back into the vice using the First Stage Work Handle (PN AT48). Tighten the Yoke Clamp Connector using a 3/4” A/F spanner. Install the Protective Cap (30) with the logo facing outwards, onto the Yoke Clamp (29). Screw the Yoke Clamp Screw (31) back into the Yoke Clamp (29), until the Protective Cap (30) is retained in place.

DIN
Insert the threaded end of the Handwheel Connector (37) through the threaded end of the Handwheel (38). Fit the Distance Piece (8) onto the Handwheel Connector. With the Valve Body held so that the inlet connection port points down, screw the Handwheel Connector into the Valve Body (7) until finger tight.
Secure the Valve Body (7) back into the vice using the First Stage Work Handle (PN AT48). Tighten the Handwheel Connector (37) using a 6mm Allen key bit in a torque wrench to 20 Nm.

Don't see torque specs for the yoke...

No other mention of any torque specs in the manual with the exception of the turret retaining bolt.
Carefully press the Turret (10) onto the Valve Body (7), ensuring the ‘O’ ring (9) remains in the correct position. Insert the Turret Retaining Bolt (19) into the Turret (10) and tighten using a 6mm Allen key bit in a torque wrench to to 8 Nm.

 

[Zung]

DST & UST Maintenance Manual, Document No. AP5824, Issue 3, 9/12/2005, page 15:

 

[ScubaSteve]

they were in inch lbs, sorry. Working on mech engineering senior design projects and everything we do is in ft. lbs. Numbers were right, wrong units.

This is a good example of why it is a good idea to have the procedures and follow the procedures for all services. We are, after all, just human and will err from time to time (even the best of us). We limit our exposure to such slip ups by saying we will follow the service instructions every time. Not picking on anyone here, just pointing out that schit does in fact happen and the procedures/instructions (which will sometimes include torque specs) can help avoid such incidents.