Frequently Asked Questions
Q: Which synthetic materials can be connected by glue?
A: All the synthetic materials we use, can be glued.
You require a cleaner and special glue, both of which you can get
from us.
Q: Which synthetic materials can I use if the flammability rating is
B1?
A: You can use PVC, PPs and PPs-el.
Q: You can you connect different synthetic materials to each other?
A: Different synthetic materials can be connected by a
flange. Even metal and plastic ducts can be connected in this way.
You can also use soft collars with straps for the pipelines to be
connected as long as these are suitable for the temperature and
pressure conditions in the pipeline.
Q: How do I know what the right wall thicknesses are for my ducts?
A: DIN 4741 Part 5 lists the specifications for the wall
thicknesses to be used, depending on the dimensions of the duct and
the pressure and temperature. In practice, however, you usually use
thinner wall thicknesses and ensure stability using interior or
exterior reinforcement. We will be happy to calculate the wall
thicknesses for your concrete application. Interior reinforcements
are usually cheaper than exterior ones. As plastic ducts are mostly
used as exhaust vents, and are therefore used in low-pressure
applications, interior reinforcements are first choice here.
Q: Why can't I select pipes with different wall thicknesses for PPs
pipes?
A: PPs pipes are exclusively manufactured with the wall
thicknesses listed in the catalogue. PPs pipes do not have various
pressure stages such as, e.g. PE pipes. For this reason, PPs pipes
are also not suitable for laying in the earth.
Q: Which synthetic material is UV resistant?
A: Only PE is UV resistant. We therefore recommend that you
only use PE for outdoor applications. PE is also the suitable
synthetic material for outdoor use due to its wide temperature range
(minus 50°C to plus 80°C. PVC and PPs-el are also
partially UV resistant. However, their disadvantage is that they are
not suitable for temperatures under
0°C.
Q: Can PVC still be used at all?
A: Of course you can still use PVC ducts and pipelines. In
some cases, PVC is indispensable! PVC can be easily worked and is
more inherently stable than some other synthetic materials. However,
some building authorities have forbidden the use of PVC. This
applies, for instance, to all public buildings in NRW, Germany.
Q: What does explosion protection mean when referred to ventilators?
A: Ventilator explosion protection refers to the electrical
equipment used (motors, switches). However if ventilators must be
completed protected from explosion then this is insufficient. In
such cases, the ventilator housing or running wheels or both must be
made of electrically conductive synthetic materials.
Q: How can I control explosion-protected motors?
A: Explosion-protected motors must be encased pressureless
to be able to control them with a frequency converter. In some
cases, these motors have very long delivery times.
Q: Can I use a step transformer to control a 400 V motor?
A: No, because you need special motors for this. The motors
installed in our ventilators are not suitable for this.
Q: Why can't I buy any air ducts direct from the warehouse?
A: We produce our ducts, moulded parts, ventilators, covers
etc. individually on order because the amounts required are
insufficient for series production. Nevertheless, delivery times are
relatively short compared to some other series products (just think
of furniture, motors, cars, etc.).
Q: Who installs the parts I have ordered?
A: If you cannot install them yourself, or do not want to,
then consult us. We will give you the names of qualified installers.
Q: Where can I get welding equipment for synthetic materials?
A: You can purchase or lease this equipment from us. As
described on the service page, we lend out this equipment for free
for 5 working days (order related).
Q: Why don't outdoor staff come to visit?
A: In the era of telecommunication and Internet, we think it
is neither economical not ecological to have field staff. However,
if you need concrete advice then you can arrange to come visit us at
any time.
Q: Do you think this list of questions is incomplete?
A: Then please drop us a line - we always
try to publish the most frequently asked questions