Steel lined ptfe equipment is usually made
with discharge port, feed port, perspective mirror, etc., but how to
successfully apply this kind of pipe port in the complex head intersecting
line, of course, our answer is welding, then how to welding?How to control the
temperature of ptfe welding?Below we tell one by one.
1, ptfe head pipe mouth production
PTFE pipe welding on sealing head to first
of all, we should make PTFE sealing head nozzle, according to the size of the
nozzle diameter steel head and according to certain proportion by using powder
moulding process manufacturing nozzle, 8 hours of sintered under the 380 plus
or minus 5 degrees Celsius, after the completion of the sintering good nozzle
with lathe car to the right size, to the congratulations of PTFE tube at this
moment you have finished.
2, ptfe head opening
Put the extracted head into the steel head,
and use the principle of light transmission to accurately open the head, pay
attention to the ptfe head must be consistent with the steel head, or the final
equipment is prone to bulge, rupture and other potential hazards.
3, ptfe pipe mouth welding
By the first two steps, we can carry out
PTFE welding. Here we know that there are two ways of welding (hot pressure
welding and hot air welding). We will explain them one by one.
(1) hot pressure welding
Before hot pressure welding we should know
the necessary theoretical knowledge, hot pressure welding is a kind of hot
welding, provide sufficient heat and enough pressure.Here, we must ensure that
the welding interface temperature must reach 673.15k and the pressure reaches
1-2mpa. Therefore, in order to ensure the welding, we need to make
corresponding molds to ensure the successful completion of the thermal pressure
welding.When all is done, the FEP film can be welded by pressurizing and
heating the interface between the nozzle and the head.
(2) hot air welding
Similarly, ptfe hot air welding is a kind
of hot welding, which is much simpler than hot pressure welding and does not
require so many molds. After placing the pipe mouth, PFA welding rod and hot
air welding gun higher than 713K are used to preheat PFA first and then place
it on the welding seam for continuous welding.
Note: whether it's hot pressure welding or
hot air welding welding temperature will be higher than the melting point of
ptfe, ptfe is possible under the temperature cracking, produces in the process
of pyrolysis perfluorinated isobutylene and other poisonous gases, so the
welding should be in a ventilation environment, when the condition does not
allow such as the four fluorine lining tank welding in production must use the
fan air supply air flow assurance and wearing a gas mask to ensure security at
the same time.
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