Another “Filter Leaks on Startup” Question

[Bcorig]

Background: Pentair 420 4 Cartridge Filter, Intelliflo VF-3050 3 HP. O ring last changed 2 and 1/2 years ago.
Situation:
1. Routine disassembly and reassembly yesterday to clean cartridges. O-Ring inspected and lubricated. Clamp-ring is secured using the “rubber mallet technique” while progressively tightening the bolt to the point were “you can just see the coils touch”. Startup was uneventful - no leaks.
2. This morning on startup there was literal gushing from the 3 articulated points on the collar and and the T bolt. Now I’ve seen a little squirt now and then after reassembly, which eventually stops - I wrote it off to “that’s the way it is’. But this was torrential.
Actions Taken
1. Rubber mallet around the collar. No change
2. Loosen the bolt - I’ve read that if its too tight this can happen - no change
3. Retighten the bolt - no change
4. Then, while it was gushing I tapped directly on the bolt and the gushing suddenly stopped
5. Stopped and started and gushing returned but eventually stopped and I called it a day. Don’t want to over-tighten.
Possible causes
1. Needs a new O-Ring
2. Too tight
3. Too loose
4. Needs new collar
If anyone is still reading It’s always been a gripe that the parameter used for ideal collar tightening are subjective “until the coils barely touch”. Is there a torque-wrench setting I can use to make it more exact?

 

[HermanTX]

I would disassemble and check the seal ring as well as the top and bottom housing where the seal ring sits. You may have some debris on those areas or maybe a slight cut on the seal ring.
I always tighten until the spring coils touch one another
Also important that the top housing sits properly onto the bottom housing with seal ring sandwiched between it. The steel ring should be positioned behind the seal ring.

 

[1poolman1]

Background: Pentair 420 4 Cartridge Filter, Intelliflo VF-3050 3 HP. O ring last changed 2 and 1/2 years ago.
Situation:
1. Routine disassembly and reassembly yesterday to clean cartridges. O-Ring inspected and lubricated. Clamp-ring is secured using the “rubber mallet technique” while progressively tightening the bolt to the point were “you can just see the coils touch”. Startup was uneventful - no leaks.
2. This morning on startup there was literal gushing from the 3 articulated points on the collar and and the T bolt. Now I’ve seen a little squirt now and then after reassembly, which eventually stops - I wrote it off to “that’s the way it is’. But this was torrential.
Actions Taken
1. Rubber mallet around the collar. No change
2. Loosen the bolt - I’ve read that if its too tight this can happen - no change
3. Retighten the bolt - no change
4. Then, while it was gushing I tapped directly on the bolt and the gushing suddenly stopped
5. Stopped and started and gushing returned but eventually stopped and I called it a day. Don’t want to over-tighten.
Possible causes
1. Needs a new O-Ring
2. Too tight
3. Too loose
4. Needs new collar
If anyone is still reading It’s always been a gripe that the parameter used for ideal collar tightening are subjective “until the coils barely touch”. Is there a torque-wrench setting I can use to make it more exact?

From the manual (attached):
PROCEDURE:
1. Be sure the O-ring is clean and in position in the lower tank half. Press the Clean and Clear® Plus Cartridge Filter lid onto the lower half so the O-ring fits in between the tank halves.
2. Hold the ends of the clamp ring apart and place over both upper and lower tank flanges. Bring the ends of the filter clamp together.
3. Insert the T-bolt through the other side of the clamp and hold together.
4. Place the small washer onto the T-bolt.
5. Place the spring, large washer and barrel nut on to the T -bolt and tighten the nut by hand. Be sure the clamp ring fits easily on the tank flanges.
6. After tightening by hand: a. Use a 7/8 in. wrench (ratchet wrench recommended) to tighten further. b. Tap around the outside of the clamp ring with a rubber mallet (or similar tool) multiple times around the entire clamp to fit the clamp properly. c. Continue to tighten until the spring coils touch. d. Tap around the entire clamp again and verify the spring coils remain touching. If not, continue to tighten the nut. Note: The clamp is installed correctly only when the spring coils remain touching after tapping the clamp(See Figure 5).7. Close the waste drain plug at the bottom of the filter.
8. Follow Start-Up Instructions exactly (see page 6).

 

[generessler]

@HermanTX has it I think. The space where the o-ring sits tapers toward the outside. Pressure forces it outward, so it seals. More pressure, better seal.

It sounds like in your case that sealing process isn't happening until you fiddle with the joint.

What might cause that:

1) Debris on the sealing surfaces as HermanTX says. For me these always have gunk on them. Keep wiping and polishing with paper towels until they come away completely clean. Both the removable top and the base.

2) Not lubricated. Use an appropriate _silicone_ grease like Magic Lube II. Coat the whole o-ring. This helps the ring slip to a stable, sealing position.

3) O-ring compressed. They gradually get egg-shaped and need replacement. Mine is 3 years old and still seals well, but ymmv. Imo it's wise to have an extra on hand anyway.

I guess damage to the sealing surfaces is also a possibility, but since you eventually do get a seal, that doesn't seem likely. Or the clamp and/or bumps it sits on are worn, so the space where the ring sits is borderline too big. That also seems unlikely unless the filter is very old. Mine is 15 years and doing fine.

 

[Bcorig]

From the manual (attached):
PROCEDURE:
1. Be sure the O-ring is clean and in position in the lower tank half. Press the Clean and Clear® Plus Cartridge Filter lid onto the lower half so the O-ring fits in between the tank halves.
2. Hold the ends of the clamp ring apart and place over both upper and lower tank flanges. Bring the ends of the filter clamp together.
3. Insert the T-bolt through the other side of the clamp and hold together.
4. Place the small washer onto the T-bolt.
5. Place the spring, large washer and barrel nut on to the T -bolt and tighten the nut by hand. Be sure the clamp ring fits easily on the tank flanges.
6. After tightening by hand: a. Use a 7/8 in. wrench (ratchet wrench recommended) to tighten further. b. Tap around the outside of the clamp ring with a rubber mallet (or similar tool) multiple times around the entire clamp to fit the clamp properly. c. Continue to tighten until the spring coils touch. d. Tap around the entire clamp again and verify the spring coils remain touching. If not, continue to tighten the nut. Note: The clamp is installed correctly only when the spring coils remain touching after tapping the clamp(See Figure 5).7. Close the waste drain plug at the bottom of the filter.
8. Follow Start-Up Instructions exactly (see page 6).

Thank you.
A few years ago I was watching a You-Tube which warned me of the dire consequences of overtightening. I think I over thought that concept and undertightened.
After reading your post I discovered the O-Ring was two years old so I got the pentair OEM part delivered and installed it today.
Secured everything to the point, Dang the torpedos, where the threads touch as described above.
Fired it up and no leaking at all.
I guess this is more about me than it is about the filter.
Thanks for the shove.

 

[4x4tx]

I am in this same boat, going to take apart and put back together today using these techniques.

also my bottom plug is leaking too, My unit is only a year and a half old. Assuming there is some dirt in there somewhere so will clean and put back. Go freezing weather coming in next week so need leaks fixed.

 

[4x4tx]

I redid mine yesterday, took my time and cleaned everything well....added some lube and it appears all of my leaks are gone as well. Thankfully