"Square" compression o ring on standard compression shutoff valve?

Old 08-27-16, 09:43 PM
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"Square" compression o ring on standard compression shutoff valve?

I have a new Hansgrohe Metric S single faucet that comes with 3/8 supply lines attached from factory. I thought it was easy as i have dome some minor plumbing work and faucet replacements before.

I have a new Brasscraft quarter turn angle shutoff valve 1/2 compress to 3/8 compression outlet installed already.

Hansgrophe faucet has a 3/8 compression inlet, but the o-ring is square/flat cut and not bevel like most supply lines you find in plumbing store. as you know, the bevel shaped o-ring will sit inside the bevel supply line valve nicely.

I don't know if the Hansgrophe supply line is a compression fitting as it doesn't have the bevel seal/o-ring that i am used to. The instruction/website doesn't help. A few sites online says they are imperial fitting, but i thought imperial pipe are straight but don't use this kind of o-ring but pipe goop or tape.

What i am worry about is that since the 3/8 compression output on the shutoff valve has a 'sharp' edge where the typical beveled shape supply lines fits properly, do need to find a new valve or adapter? I am worry that if i tight it down hard, the shutoff valve's bevel edge will cut the faucet's supply line o-ring and cause it to not seal properly.

Old 08-28-16, 04:39 AM
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The flat cut washer is fine, Moen uses the same nut and it's far superior to any supply line you will find in a store.
Do not overtighten.... it doesn't take much to seal the connection and torqueing it down will cause leaks.
Hand tighten the nut firmly and add 1/4 - 3/8 turn with a small wrench. I've never seen a line like this leak.

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