How to fix a thermos cap with a button or valve

How to disassemble the thermos cap to clean or replace parts? Some models are threaded and easy to fold out; others will have to use additional tools. In general, the procedure is simple and accessible to any user.

Cover device with valve

The valve in the thermos is an elastic disk with a spike in the center. A spring and a fixing washer are put on the spike. The latter is supported by a cone-shaped thickening at the end of the spike.

When the owner presses a button on the cover, the valve lowers and passes fluid to the overflow holes. When you press the second button or the same (depending on the type of locking mechanism), the valve fits snugly and closes the leak.

How to disassemble

The best option is if the cover has a threaded fastener. All that is required:

1. Unscrew the ring with the button / buttons.
2. Push out the valve.
3. Remove locking washer and spring.
4. Pull the stuffing box - elastic ring from the lower rim of the cover.

All details must be washed from tea or limescale, crumbs, tea grounds, etc.

In older thermoses, the valve disc breaks or loses its elasticity over time. Theoretically, you can replace it with a new one, but in practice, these parts are usually not sold, and you have to replace the entire cover.

Chinese thermos with button:

1. Pull out the valve with force.
2. Place a sufficiently long self-tapping screw in the hole for its spike and push out the mechanism with buttons.
3. Remove all gaskets, springs, and lock washer to flush.

Tip
Sometimes a new cap allows fluid to leak because the gaskets and valve disc are not designed. Lower the bottom of the lid in hot water before first use for 5-10 minutes, then gently and completely tighten on a thermos.

How to fix a drop down valve

One of the problems that do not immediately make itself felt is the abrasion of the retaining washer on the valve spike. Over time, it begins to hold the spring poorly, and the valve flies, falls into a thermos, and the liquid spills out through overflow openings.

Replacing the washer is quite simple:

1. Cut a suitable circle from the plastic cover and make a cross-shaped cutout in it (it is convenient to carry out the operation with a plastic knife, which is included in the set of modern burners).
2. Choose a plastic dowel of a suitable diameter, cut off the hat with an office knife and use it as a retainer.

purity.bigbadmole.com/en/ magazine draws your attention: the more complicated the cover design, the higher the probability of breakage. The most reliable are blank covers with a sealant, however, they must be washed periodically to remove plaque.

Most covers with a valve or button are disassembled, and this allows you to clean them and extend the service life. The operation is quite simple, and it should be done at least once a month, if the thermos works a lot.