Trade press article
Georg Fischer Piping Systems Ltd.
8201 Schaffhausen
Switzerland
www.piping.georgfischer.com
Ralph Schreiber
Public & Media Relations Manager
Tel +41 (0) 52 631 3374
Fax +41 (0) 52 631 2830
Mobile +41 (0) 79 830 2803
ralph.schreiber@georgfischer.com
Schaffhausen, December 2009
Optimal jointing technology
Material, application and medium are the key criteria for selecting the jointing
technology. GF Piping Systems offers its customers not just products and
know-how, but also a complete service package with training, fusion machines
and tools and logistics services.
Even if pipes, fittings and valves are our core business, GF Piping Systems has
always focused on the jointing technology as well. In the early days it was the
development and manufacture of various types of thread cutting machines and tools,
which were used for the malleable iron fittings; these were followed by the invention
and production of the “Type T” adhesive for PVC jointing, and iFIT (the push-fit fitting),
and BCF (bead and crevice-free) and IR (infrared) fusion. Today's product offering
includes many different types of jointing technologies with which the same or different
materials, pressure ratings and dimensions can be connected. These connections
are required in a vast array of pipework applications, whether in industry, building
services or gas and water utilities. Basically, jointing technology can be divided into
two main categories: removable and non-removable joints. What both have in
common is that they join safely and reliably, without leakage.
Among the removable joints are:
- Flange connectors
- Unions
- Adapters
- Threaded fittings
- Hose connectors
- Sanitary adapters
The non-removable joints include:
- Solvent cementing
- Butt fusion
- IR fusion
- Electrofusion
- Socket fusion
- BCF fusion
The material decides the type of jointing technology
Before the jointing technology is selected, the material must be determined. For the
non-removable joints we generally differentiate between amorphous thermoplastics
and semi-crystalline thermoplastics. The semi-crystalline thermoplastics (PE, PP, PB,
PVDF) can be fused, whereas the amorphous thermoplastics (PVC-U, PVC-C, ABS)
can in principle only be cemented. Therefore, if PVC or ABS is the material of choice
and non-removable jointing is desired, then the recommended jointing technology is
clearly cementing. Naturally, if required, a removable connection, such as a flange,
coupling or union, can also be selected for these materials. For semi-crystalline thermoplastics and a preference for fusion, one of the many different types of fusion
methods can be chosen, depending on the requirements and suitability. But the
removable connections, e.g. flanges, unions, couplings, and for PB the iFIT push-fit
connection, are also feasible solutions.
When to use which fusion jointing technique
There is no single or easy answer to this question, but the following has been
asserted: For gas and water distribution, PE is preferred and therefore electrofusion
and butt fusion are used exclusively. In industrial applications, the circumstances are
somewhat more complex because diverse plastics are utilized. This means that first
we must determine which plastic is optimal for the medium to be transported. Plastic
pipes are used to transport drinking water, industrial water as well as contaminated
water, but they are also implemented in conveying aggressive liquids and gases.
GF Piping Systems has a very useful tool to help make such decisions: the Planning
Fundamentals, which include a list of chemical resistances for the various plastic
materials.
When semi-crystalline thermoplastics (PE, PP, PVDF) are involved, a wide range of
fusion methods can be selected from according to the specific requirements. Does
the medium conveyed induce stress cracking? Then the reasonable solution would
be a fusion joint that is stress resistant, which in this case would be BCF fusion (up to
maximum d110mm). If, for example, the medium to be transported is ultrapure water,
then only IR or BCF fusion would be optimal jointing methods. If, on the other hand,
these two fusion methods are not specified from a medium point of view, then a
socket or butt fusion solution would be possible options.
When are removable joints used?
Removable joints are found in every type of piping system. Flanges are mostly used
to connect a pump or to install a valve, unions to screw components together on
location, hose connectors for tapping points and sanitary adapters in life science
applications since this type of connection in the metal range is well accepted in this
market.
Fusion welds without beads or crevices
BCF fusion guarantees obtaining a joint whose surface is just as smooth after fusion
as the pipe's surface – without beads, without crevices and particularly low-stress.
Special applications for this fusion technology are found in the life science industry,
where fusion joints that will not affect the quality of the media are required. This
means that high purity must be warranted at all times. There may be no deposits,
such as microorganic growth or biofilm. The BCF System developed by GF Piping
Systems as a combination of fusion technology and product range is ideal for use in
the pharmaceutical industry and in biotechnology. It is so efficient because the fusion
welds exhibit no undercuts or dead spaces. Since the fusion process is fully
automatic, reproducibility is guaranteed.
Contact-free fusion
In addition to BCF fusion, GF Piping Systems has also worked to develop the IR
fusion method. The no-contact approach via infrared radiation, which melts the end
face of the pipe, has the big advantage that materials, such as PVDF (the melt of
which is very sticky) can be processed much more easily and more hygienically. The
application areas are, similar to BCF fusion, mainly in the highend market: life
science, semiconductor industry and chemical process industry. The IR method is
specially suited to clean room environments. Besides the cleanliness and
reproducibility, the big advantage of IR technology is the shorter fusion time. Fusion
times are on average 50% shorter than with the conventional butt fusion method,
rendering it the fastest butt fusion technology in industrial plastic piping system
construction today.
Fast and clean
The IR-Plus fusion machines from GF Piping Systems comply with the most stringent
quality and purity requirements for fusion joints. And with the same guarantee of high
reliability, the new generation of IR-Plus machines achieves even faster fusion times.
Another benefit is the easy downloading of fusion protocols via USB interface. These
data are write-protected and can be stored and managed on a PC. The new addition
to the IR-Plus family is the IR-Plus 110, which is a very attractive product thanks to
its extremely compact design. Nearly 20 years of experience in developing fusion
machines at GF Piping Systems flows into creating customer benefit.
Complete packages
Fusion machines from GF Piping Systems, including comprehensive service
packages, can also be rented worldwide. Organizing logistics to the building site and
back, inspecting and servicing all machines before each rental, as well as the local
support of well-trained staff are the small differences that set GF Piping Systems
apart from the competition.
Author:
Felix Meier, Head of Product Management PP & PVDF, GF Piping Systems,
Schaffhausen, Switzerland
Georg Fischer – Adding Quality to People`s Lives
GF Piping Systems is one of the three core businesses of the Georg Fischer Corporation and a leading supplier
of piping systems in plastic and metal with global market presence. Connecting technology, fittings, valves,
measuring devices and pipes are used for water conveyance and treatment as well as the transport of liquids and
gases for industrial purposes. GF Piping Systems provides innovative, engineered solutions for the segments
building technology, chemical process industry, food & beverage, microelectronics, ship building, water and gas
utilities and water treatment. Sales companies in more than 25 countries and representatives in another 80
countries ensure customer support 24 hours a day. Production sites in Europe, Asia and the US are near the
customers and meet local requirements. The Georg Fischer headquarters is based since its foundation in 1802 in
Schaffhausen, Switzerland.
Key figures GF Piping Systems 2008
More than 4200 employees worldwide
1066 MCHF sales
80 MCHF EBIT
Further information is available at www.piping.georgfischer.com