Loctite 55 – Pipe Sealing Cord – 160m

Loctite 55 pipe sealing cord is a thread sealant that does the job of PTFE tape and hemp-and-paste in one go. The cord is already impregnated with sealing paste, so there is no tin to open, no brush to clean and no paste dripping down your sleeve. You wind it onto the thread, close the joint, and carry on. This 160m spool covers a fair amount of fittings before it needs replacing.

The cord is a fine, strong filament, which matters more than it sounds. PTFE tape has a habit of shredding when you overtighten, or bunching up on a coarse thread. Loctite 55 holds together, and because it is a cord rather than a flat tape, you can back off a fitting slightly to line it up without the seal falling apart. Anyone who has tried to adjust a PTFE joint by an eighth of a turn will know why that is useful.

Loctite 55 Pipe Sealing Cord Applications

Loctite 55 is suitable for hot and cold water, potable water, domestic gas, natural gas and liquefied gas in its gaseous state. It will also cope with gas condensates, compressed air and industrial oils, thanks to the silicone oil in the paste. It works on copper, steel and plastic pipe systems, so one spool covers most of what turns up on a plumbing or heating job.

Once the joint is closed tightly, the seal will withstand pressures in the region of 40 bar. That is well above anything you will meet on domestic pipework, which gives you a decent safety margin on standard installs and makes it equally at home on compressed air lines in a workshop.

Approvals and Standards

It complies with EN 751-2 and carries DVGW approval. It also certifies to ANSI/NSF Standard 61, which covers contact with drinking water. For anyone who needs to show the sealant used on a potable or gas installation is fit for purpose, those approvals are what you point to when someone asks.

Using Loctite 55 on Site

Wind the cord a few times around the thread, working in the direction the fitting will tighten so it does not unravel as you screw it home. Close the joint firmly and you are done. There is no cure time to wait around for in the way you would with some anaerobic sealants, though as with any threaded joint you should pressure test before you close up the wall.

The cord comes in a handy dispenser spool, so you can cut it cleanly without chasing the end around. It is a simpler routine than hemp: no combing out fibres, no measuring the right amount of paste, and a lot less mess in the van.

One limitation worth knowing. Loctite 55 is not suitable for heating oil or fuels. For those, Loctite recommends their 577 product instead. For everything else listed above, this cord is a straightforward replacement for the old tape-and-paste routine, and it keeps joints sealed under serious pressure.