1. The purpose of tow and how it works.
2. Varieties of sealing materials.
3. The method of sealing pipe threads tow.
In plumbing work, tow is used to seal pipes and transitions connected by a thread. It is made mainly of flax waste and is a coarse fiber of small sizes. If the tow is wound correctly, leakage protection will be provided throughout the life of the pipeline. Answering the question of how to wind the tow on the thread, it should be said that the workmanship prevents the risk of leakage in the plumbing system.
There is a gap between threaded connections through which water freely extends beyond the pipeline. If there is a properly laid plumbing tow in it, then the gap becomes smaller, and during the penetration of water into such a connection, the flax swells and the leak stops.
Varieties of sealing materials.
The main materials that create a tight layer between the threaded connections include:
- tow sanitary;
- FUM tape;
- liquid FUM.
Silicone is used as an additional material to tow, but by itself, due to its properties, it will not be able to provide reliable protection of the connection from leaks.
FUM is a winding for threads, consisting of a Teflon tape, is not wetted by water and creates a water-repellent layer in the joints.
Liquid FUM is a one-component sealant of blue color, when in contact with air it slowly hardens and forms a sufficiently strong and dense aggregate that prevents the outflow of water from the system. But, if, using the above materials, pressure testing of the water supply system can be carried out immediately, then after applying the liquid FUM, before checking the system, you need to wait a certain time, depending on the diameter and temperature of the environment.
The method of sealing pipe threads tow.
High-quality winding of the thread is carried out using the following materials and tools:
- pipe lever wrenches in the amount of two pieces;
- tow plumbing;
- FUM tapes.
The procedure for obtaining a high-quality tight threaded connection is illustrated by the example of combining a union nut (American) with an external thread of 1 inch and a check valve.
With tow, we separate the strand with a length of approximately 5 to 7 turns of diameter 1 inch and the density indicated in the photo.
The resulting workpiece is applied to the beginning of the connecting element of the American, while her thread should be directed at you, and wound clockwise, along the turns and back. The end of the tow is brought to the beginning of the thread and fingers, clockwise, smooth it. In the end, it should turn out as in the photo.
Then, we wind the FUM clockwise on this part so that it completely overlaps the plumbing flax and lies on it in 2-3 layers.
Teflon tape prevents tow from turning and moving off the part. We bait the American on the check valve and with the help of the keys we tighten them until a noticeable load occurs.
Such combined winding of the thread, with appropriate dexterity, almost always ensures a reliable joint of two detachable elements of the pipeline. When all components of the system are assembled, it is necessary to pressure test it at a pressure of approximately 1 bar and inspect all threaded connections for leaks.
When using low-quality parts, the amount of winding should be slightly reduced, since in the process of flax swelling, forces arise that can lead to damage to the part.