Sealing pipes and threads is an important step in the work of an installer. Every installation should have a perfect seal. The sealing is not supposed to cause damage due to water or gas leaks. Depending on the state of our wallet, the pipe material or the type of installation, we can distinguish between several sealing methods with unique properties.

Sealing of pipes with packing material

Packet sealing of pipes is the most traditional method. It works well for water and gas installations. Poults are made by mechanically processing flax and hemp fibres, where carded yarn is the target material and inferior fibres, i.e. pitch, are used for sealing. The poults are soaked in sealed lead mica (which oxidises iron, but should be watched out for due to its unfavourable properties) and varnish, which has an anti-corrosive effect.

Packets (of hemp) are needed for the sealing operation: Hemp packets 100g or a reel with a dispenser: Hemp packets spool 80g in dispenser) and a special sealing paste (e.g. Sealing paste AGAM 500g, LENPAK sealing paste 500g water/gas). To make sealing more efficient, the external thread of the pipe to be joined must be prepared with a blade. The end is scraped until it is rough, which affects the comfort and stability of the packing. A fibre pack is wound onto the surface of the pipe, which is then lubricated with sealing paste. If the steps are performed in the reverse order, the packets will slip over the threads. In order to maintain a complete seal and prevent the packets from rotting, we cover them again with paste at the end of the operation.

If one does not have experience in sealing with packets, the disadvantage may be an unsightly appearance of the seal due to protruding fibre ends.

Sealing of pipes with Teflon tape

Teflon is a popular PTFE agent that is perfectly airtight. Sealing threads with Teflon tape (e.g. Teflon tape gas 12 mm (12mb) roll, Teflon tape 12 mm (10 mb) roll) is very similar to that using tacks. A tape of the required thickness is wound onto clean and degreased external threads and applied. It is important that the individual coils are not visible. The application of the tape must be carried out with due accuracy and care. Any undoing during threading will result in rupture of the tape and, consequently, in leaks.

Sealing of pipes with thread

Sealing thread (e.g. LOCTITE Teflon thread sealing thread 150 m, Thread sealing thread LOCKER 150 m) comes in handy where there is a problem with a leaking hose, e.g. when fitting a new mixer tap at a sink or bathtub. It is small and inconspicuous and easy to apply.

The threads we use to seal the pipes are from:

• Teflon (PTFE) - more resistant to temperature changes, but has the same disadvantages as Teflon tape,
• polyamide (PA) - less likely to break.

In each case, the thread in question is wound onto the clean and degreased thread. It is then screwed firmly onto the remaining pipe or section of pipe. A well-made seal retains its tightness when backed off by a maximum of 1/9 turn.

Sealing with anaerobic resin

Anaerobic (anaerobic) resin is not a very popular sealing method. Perhaps because it is only used for metal threads and is a demanding material. It will not work well with pipes larger than 2" in diameter as it can have curing problems. It polymerises at temperatures above 10 degrees Celsius.

Anaerobic resin (e.g. Anerobic paste 50ml tube) is applied to a degreased, clean thread with an applicator, although it is usually recommended to leave the first two grooves free. The polymerisation time - depending on, among other things, the material, size of the surface - can take several minutes or even tens of hours. Sealing with anaerobic resin allows any manoeuvring of the joint before setting. You can read about sealing pastes in a separate article.

Proper sealing is extremely important for domestic installations. Seals keep water and gas pressurised at all times while effectively insulating them. It's worth looking around among the different sealing methods and determining your needs. Assess your financial capacity and the time you can devote to the sealing operation.