GRP pipe is also known as glass fiber winding sand tube (RPM tube). It mainly uses glass fiber and its
products as reinforcement materials, unsaturated polyester resin and epoxy resin as basic materials and
inorganic non-metallic particle materials such as quartz sand and calcium carbonate as filler as the main
raw materials. The standard effective length of the tube is 6m and 12m, and its production methods are
fixed length winding process, centrifugal casting process and continuous winding process. Products can
be classified according to the process method, pressure grade PN and stiffness grade SN.
Description
GRP pipe with its unique strong corrosion resistance, the surface is smooth, conveying low energy
consumption, long service life (above 50 years), transportation convenient installation, low maintenance
cost and low comprehensive cost a lot of advantages in the oil, electric power, chemical industry, papermaking,
urban water supply and drainage, sewage treatment and seawater desalination plant, the gas conveying industries
has been widely used.
As China’s urbanization process is accelerated, in the face of the balance of population, resources and environment
and protection, governments at all levels from one year to increase investment in urban infrastructure, and to meet
the needs of advanced science and technology, constantly enrich pipes, pipe fittings of varieties and specifications,
production continues to increase, constantly improve the quality, especially the plastic tube development faster,
become today’s investment hot spots. GRP pipe is one of them.
Characteristic
- Good corrosion resistance. Due to the glass fiber reinforced plastic main material selection of polymer
composition of unsaturated polyester resin and glass fiber, can effectively resist corrosion of acid, alkali,
salt and other medium and untreated sewage, soil corrosion, chemical waste water and liquid chemical erosion,
in general, long-term to maintain safe operation of pipeline. - Good aging resistance and heat resistance. GRP pipe can be used in the temperature range of -40℃~70℃ for a long
time, using a special formulation of high temperature resistant resin can also be more than 200℃ temperature normal
work. For the pipe used in the open air for a long time, its outer surface is added with ultraviolet absorber, to eliminate
ultraviolet radiation on the pipe, delay the aging of FRP pipe. - Good frost resistance. When the temperature is below -20 ℃, the pipe will not freeze and crack.
- Light weight, high strength, convenient transportation. GRP pipe is not only light in weight, high in strength, strong in plasticity,
convenient in transportation and installation, but also easy to install all kinds of branch pipe, and the installation technology is simple. - Good hydraulic conditions. Smooth inner wall, strong conveying capacity, no scaling, no rust, small water resistance.
- Good designability. GRP pipe can be designed and manufactured into different pressure grades and stiffness grades
according to the user’s specific requirements, such as different flow, different pressure, different buried depth and load
conditions. - Low maintenance cost. GRP pipe because of the above corrosion resistance, wear resistance and anti-freezing and
anti-fouling properties, so the project does not need to carry out anti-rust, anti-fouling, insulation, heat preservation
and other measures and maintenance. There is no need for cathodic protection for buried pipe, which can save more
than 70% of project maintenance cost. - Good wear resistance. The water containing a large amount of mud, sand and stone is put into the pipe to carry out
the contrast test of rotary wear effect. After 3 million rotations, the depth of wear on the inner walls of the tubes was
as follows: 0.53mm for tar and enamel coated steel tubes, 0.52mm for epoxy and tar coated steel tubes, and 0.21mm
for glass steel tubes treated with surface hardening. Therefore, FRP has good wear resistance. - Good thermal insulation. Fiberglass is a non-conductor, the electrical insulation of the pipeline is excellent, the insulation
resistance is 1012~1015 ω.cm, the most suitable for the use of power transmission, telecommunications lines in dense
areas and mined areas of fiberglass heat transfer coefficient is very small, only 0.23, is five thousandths of steel, excellent
insulation performance of the pipeline. - Small friction resistance and high conveying capacity. The inner wall of glass steel tube is very smooth, roughness and
friction resistance is very small. The roughness coefficient is 0.0084, while the n value of concrete pipe is 0.014 and cast iron
pipe is 0.013. Therefore, glass pipe can significantly reduce the fluid pressure loss along the process and improve the conveying
capacity. Therefore, significant economic benefits can be brought. When the conveying capacity is the same, FRP pipes with smaller
inner diameter can be used in the project, thus reducing the one-time project investment. Using pipes with the same inner diameter,
FRP pipes can reduce head loss and save pumping costs compared with other pipes. In addition, FRP piping can shorten
pumping time and reduce long-term operating costs.
Production
There are three main types of glass steel pipe production processes: reciprocating fiber winding process,
continuous fiber winding process and centrifugal pouring process.
Reciprocating filament winding process (n) : in this process, the leaching glue tank with rotating mandrel
for reciprocating motion, the long fiber glass with a certain Angle relative to the mandrel axial auxiliary,
auxiliary Angle (that is, the winding Angle) baptism glue tank movement speed and the ratio of the core
mold speed control, soak glue tank translational motion by computerized machine electric control. The
number of winding layers is gradually increased until the designed wall thickness is reached. After winding,
the resin in the product is basically cured. After curing, the core mold is released from the glass steel tube.
Continuous fiber winding process (continuous method) : this process is the tube in motion through a feeding
station for resin preimpregnated untwisted roving, cut FRP fiber and resin sand mixture, the tube is made in
the continuous progress of the core mold.
Centrifugal pouring process (n) : in this process, using glass fiber reinforced materials and sand, feeding on
the bearing steel in the mould, injection plus unsaturated resin catalyst in die end, make its dipping reinforced
material, under the effect of centrifugal force, the resin exchange fiber and filler in the air, so as to create a
nonporous compact composite material, Due to centrifugal force, the inner wall of the pipe forms a smooth,
smooth, resinous inner surface layer, and the pipe is cured at higher temperatures. The tube made by this
method is also called glass fiber reinforced plastic sand tube.
Reciprocating fiber winding process is used by more manufacturers in the world than the other two production
processes, one of the reasons is that reciprocating fiber winding process of glass steel pipe has a wider range
of uses, applicability is better.
Matters needing attention
- Due to the small density and light material, it is necessary to set anti-floating measures such as town pier
or rainwater runoff dredging when installing glass steel tube easily floating tube in areas with high groundwater level. - In the construction of tee opening on the installed GRP pipe and repairing pipeline cracks, the requirements are similar
to the completely dry conditions in the workshop, and the resin and fiber cloth used in the construction also need 7-8
hours to cure, but the on-site construction and repair is generally difficult to meet this requirement. - Existing underground pipeline detection equipment is mainly used to detect metal pipelines, while non-metallic pipeline
detection equipment is expensive. Therefore, GRP pipes cannot be detected after being buried in the ground, and other
subsequent construction units are easy to dig and damage the pipes during construction. - GRP pipe uv resistance is poor. The aging time is delayed by making 0.5mm thick resin rich layer and uv absorbent on the
surface. Over time, the resin – rich layer and uv absorbent will be damaged, which will affect its service life.
The depth of soil covering is higher. The shallowest soil covering SN5000 class GRP pipe under general roadway is not less than
0.8m; The deepest overburden is not more than 3.0m; The shallowest soil covering of SN2500 GRP pipe is not less than 0.8m;
The maximum soil cover is not more than 1.2m(the minimum and maximum soil cover of 12mm thick steel coil pipe are 0.7m and
4.0m respectively).Backfill soil shall not contain more than 50mm brick, stone and other hard objects, so as not to damage the outer
wall of the pipeline. - At present, there are no reports about large-scale use of GRPpipe by large water companies in China, and the service life of GRP
pipe is unknown because it is a new type of pipe.
Incoterms (price terms)you should know
Before commencing with global buying and shipping in large orders, we recommend you to get acquainted with Incoterms
(International Commerce Terms). Simply put, these are rules set by the International Chamber of Commerce (ICC), involving
certain selling terms used globally. These are the terms agreed upon by both buyers and sellers during any international transactions.
The Incoterm you agree upon will determine whether you or your seller are legally subjected to certain costs and risks when your
goods are in transit. There are several different Incoterms, but usually being familiar with the following four is enough for China imports:
EXW – Ex-Works or Ex-Warehouse
Shipping under EXW makes it the supplier’s responsibility only to get the goods ready for dispatch. From then on, the freight
forwarder is responsible for receiving the assets and make sure they are cleared, loaded onto the cargo vessel, and delivered
to their final destination.
FOB – Free on Board
With FOB, the supplier has to get your goods aboard the vessel. Once the goods are loaded, the supplier is no more responsible
for them. The freight forwarder should handle them thereupon, until delivery.
CIF – Cost, Insurance, and Freight
When shipping under CIF, the seller loads the goods on the vessel, upon which the risk of any loss or damage passes, just like in
FOB. Additionally, in CIF, the seller covers all freight costs until the goods arrive at your destination port. The seller also has to
insure the goods to cover the risk of damage during carriage.
Main shipping methods we can choose?
Shipping Method: by sea, air or courier?
By Sea
Shipping by sea (Full containers)
Shipping by sea (Less than containers)
Shipping by sea (Bulk vessel)
By Air
A plane can usually ship anything that can be shipped LTL. Air shipping is a fast option but can be a fairly expensive
way to ship freight to other countries. However, if you‘re on a time crunch it‘s probably a good option.
By Courier
Such as DHL/EMS/TNT/FEDEX/ UPS etc.
Shipping Container Size
Typically, there are 4 options when it comes to shipping containers.
FCL 20 feet
FCL 40 feet
FCL 40 feet HQ
FCL 45 feet HQ
20” is designed to carry more weight than voluminous cargo.
Example – minerals, metals, machinery, etc. all of which are heavy goods.
40” is designed to carry voluminous cargo rather than heavy cargo.
Example – furniture, types, clothes, etc, all of which are voluminous goods.
If you are able to shape your order based upon how many units will fit in a specific container size, you may be able to save quite a bit of money.
If you plan to import GRP pipes , Contact us now!
Inquiry please contact.
Email ✉: cn@chinaestop.cn
Whatsapp✆:+86 15350598856
Web: www.chinaestop.cn
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