The Internal Structure of the FRP Storage Tank and Repair Method

 

 

Not many people know the internal structure of FRP storage tanks. FRP tank wall is divided into an internal layer, secondary internal layer, and external surface. Next, we introduce these internal structures.

 

FRP storage tank internal structure

1. FRP tank lining layer

FRP storage tank lining layer consists of the inner surface layer and secondary inner layer, the matrix should be used bisphenol A type unsaturated polyester resin, vinyl ester resin, and other resins with excellent corrosion resistance. Reinforcing materials are glass fiber surface felt, glass fiber short-cut raw silk felt and glass fiber untwisted roving cloth, etc.

2. FRP storage tank secondary inner layer

It is made of general-purpose unsaturated polyester resin as the matrix and glass fiber twist-free roving as the reinforcing material. Resin content is 45%-50%, the thickness of the layer is determined by the design calculation.

3. FRP storage tank outer surface layer

The unsaturated polyester resin with excellent weather resistance is used as the matrix, and the glass fiber surface mat or glass fiber untwisted roving cloth (thickness less than 0.16mm) is used as the reinforcing material, with resin content more than 55%, and the thickness of the layer is 0.2-0.5mm.

 

Repair of FRP storage tank

Although the FRP performance is superior, in terms of hardness, corrosion prevention is good, but also for one reason or another, resulting in FRP storage tank leakage, and FRP damage, in most cases to replace the main, repair is very difficult, usually with the gluing method or hot welding method to restore it, here is a brief introduction to the gluing method of repair.

(1) cleaning FRP storage tank. First of all, the damaged tank will be disassembled first, clean and dry it, and do the prerequisite work of repair.

(2) according to the size of the broken part cut appropriate large glass fiber cloth, after baking wax removal, heating until not smoking, take care not to fold.

(3) Glue preparation. There are many kinds of glue formulations, but in general, the epoxy resin and polyamide resin two kinds of resin in the ratio of 1:1 into a wide mouth container, stirring with a stick, the viscosity is generally good to lift the stick does not pull the wire, pay attention to the principle of rather less than more, not too much at a time, to just enough to use up as good, followed by uneven mixing, with a good glue after a period of time will be Self-curing, resulting in waste.

(4) Apply glue. First, use a stiff brush to brush a layer of glue in the inner surface of the glass fiber reinforced plastic tank, and then the prepared glass cloth on the surface of the glue, gently pat the pressure to make it fit tightly so that the glue penetrate the glass cloth; the first layer of good penetration and then coated with a second layer of glue, paste the second layer of glass cloth. So the cycle coated a few layers on it, take care not to get too thick in the coating and framing.

(5) Curing. After painting a higher temperature place to let its natural curing, although it takes a longer time, but definitely not with open fire baking. Wait for its natural curing, and then polish the edges, openings, after spraying, the repair is complete, the glass fiber reinforced plastic tank and restore the strong and durable.

 

We are an FRP storage tank supplier, please feel free to contact us if you need them!

Can FRP pipes be customized?

FRP (glass fiber reinforced plastic) has good designability, shape performance and easy maintenance. Compared with steel, FRP (glass fiber reinforced plastic) has very high corrosion resistance, the specific gravity of 1.5 to 1.9, much lower than steel's 7.8, but its mechanical strength is higher than steel, FRP containers have the advantages of a low coefficient of thermal expansion and good insulation performance, and have been widely used in many fields Applications.

 

According to the shape of the medium, FRP containers can be divided into three categories: liquid, gas and solid tanks; according to the pressure level, they can be divided into two categories: ATM tanks and pressure tanks; according to the shape of containers, they can be divided into three categories: horizontal cylindrical tanks, vertical cylindrical tanks and rectangular tanks; and PVC/FRP, PP/FRP and PVDF/FRP composite tanks.

 

Hebei Yongchang Composite Technology Co., Ltd. is a professional FRP container manufacturer in China. With exquisite technology, reliable quality and good reputation, Hebei Yongchang FRP containers are widely used in chemical fertilizer and pesticide, electronic and electric power, pharmaceutical, petrochemical, water treatment, citric acid and food fermentation, and can be manufactured with a maximum diameter of 25000mm, volume is 5000m.

 

Special attention needs to be paid here.

When ordering FRP pipe, the following data needs to be provided to us.

Pipe diameter

Design and working temperature of the working fluid.

Design, operating, surge, vacuum, and test pressures.

Live load of the buried pipe.

Maximum/minimum burial depth and trench width.

Detailed information on soil properties and trench preparation.

 

Yongchang FRP pipe performance and characteristics

1. Corrosion resistance: Different types of anti-corrosion lining resins are selected for different acid, alkali and salt environments, as well as various oils, seawater and organic solvents.

2. Lightweight, easy to maintain and durable.

3. Easy to install: There is no technical limitation on the length of the FRP pipeline, but considering transportation, the length of the pipeline is generally less than 12m, so the number of joints is greatly reduced. Due to the lightweight of FRP, the pipeline can also be installed manually or by light installation equipment, which is convenient and fast.

4. Good applicability: the existing FRP pipeline standard diameter is between 25mm-4000mm, the long-term pressure-bearing capacity is generally less than 1.6Mpa, and according to the special needs of users, it can reach a higher pressure of 6.4Mpa.

5. High conveying capacity: smooth pipe wall N-S 0.0084. It has a higher flow rate compared with a traditional pipeline of the same diameter, so it can save pump energy and prolong project life.

6. Low permeability: Due to the good sealing connection and the longer length of each pipe, FRP pipes have lower permeability than traditional pipes, thus greatly reducing the risk of groundwater infiltration into the pipes and media penetration as well as pollution of the environment.

7. Strict testing standards: Our company has advanced testing equipment and strictly enforces inspection standards to ensure product quality. Relevant standards: ASTM, AWWA, ASME, etc.

8. Low cost and long life: Hebei Yongchang FRP products have a long service life, basically no maintenance, and very low installation and transportation cost.

 

FRP pipe connection requirements

Interface operation, the ambient temperature is not less than 10 ℃; curing temperature after bonding is not less than 15 ℃, curing insulation time is not less than 12 hours. Paste the interface according to the layer design. According to the sample data, planned gel time, ambient temperature, etc., mix the resin and stir it thoroughly. When the bonding thickness is more than 10mm, it should be formed in stages. Before each molding, the curing surface of the last molding should be sanded.

 

Our Yongchang FRP / FRP pipes are designed and manufactured according to customer requirements in various sizes and configurations. We can manufacture pipes of any size and pressure and can make composite pipes such as PVC/FRP, PP/FRP, PVDF/FRP, etc. according to the conditions of use. Our designers can calculate the circumferential stress, axial stress and bending Poisson's ratio coefficients of products based on your available space, chemical fluid requirements and applicable natural conditions, and then give product selection, product thickness and layering. We have detailed manufacturing process parameters. All of our pipe designs meet industry standards such as ASTM D2996 Standard Specification for Fiber Wound "Glass Fiber" (Glass Fiber Reinforced Thermoset Resin) Pipe for Fiber Wound Pipe.

 

Common codes and standards that govern the details of FRP pipe are

ISO 7370

ANSI/AWWA C950

AWWA M45

ISO 14692

AWWA C590

ISO 10467

BS 5480

ISO 10639

ASTM d2996, ASTM d2997, Astm d5421, Astm d4024, Astm d5685

 

Yongchang offers long-term corrosion solutions and the absolute longest product life for standard fiberglass tubes, custom tubes, special manifold systems, pipes, or chimneys. Contact us and you can get advice from our professionals depending on the use scenario!

Guide to installing FRP pipes

Although installation is not usually considered part of the design of a piping system, it is an important part of a successful system and we feel it needs to be emphasized here. There is no doubt that more problems occur in FRP piping systems due to improper installation than any other single cause, and there are many steps that must be followed to ensure that problems do not occur in the future.

 

① FRP pipe should be inspected for appearance and size before construction, and accepted according to the factory certificate of conformity.

② Pipeline installation drawings are the basis for pipeline installation works, the laying of FRP/PVC pipe (including the form of connection, coordinates, elevation, slope, slope direction, etc.) support, FRP/PVC pipe and equipment, pipeline accessories connection, pipeline accessories installation location, support, etc., should be in line with the design drawings, such as changes, must be resolved in consultation with the design unit.

③ Pipe installation, according to the pipe section divided by the pipe installation diagram, can be installed from one end of the pipe in order to the other end of the pipe accessories, and then set up brackets or supports (if necessary, temporary support is required during the installation process). When the pipe is lifted, the outer wall surface must take protective measures, and direct contact with the wire rope is prohibited, so as not to cause local stress.

④ The connection point of FRP pipe is only allowed in the straight pipe part. The distance between the butt welding connection point and the edge of the pipe support should be greater than the outer diameter of the pipe and not less than 100mm; the distance between the socket connection and the edge of the pipe support should be greater than 150mm.

⑤ The connection structure of the pipe is in the form of socket connection, flange connection (welded ring flange connection and composite flat welding flange connection), and butt welding connection. This project will determine the installation method according to the specific requirements of the design documents.

(6) The installation workers engaged in welding must hold a welder's certificate and be familiar with the performance of FRP/PVC pipe adhesive and its installation method, and have skilled PVC welding operation ability.

(7) Before the pipe is connected by socket, the inner wall dirt of the PVC pipe should be removed from the connection, and then the socket should be inserted into the socket, and the socket should not be skewed, cracked or other defects, and the socket depth should be reached before PVC welding is carried out.

⑧ The socket part should be enhanced by FRP, evenly coated with a layer of R glue at the enhancement, coating thickness is uniform, shall not leak and flow, then wrap a layer of glass cloth, coated with unsaturated resin, wrap glass cloth, repeatedly until the thickness reaches the requirements.

⑨ When the socket installation fails to pass the need for rework, the socket plug and socket must be re-made, and shall not use the used socket plug.

⑩ When flange is connected to the pipe, both inside and outside sides must be welded to the pipe, the flange surface and pipe axis inclination should be less than or equal to 1/100 of the outside diameter of the pipe. flange connection should be strictly aligned, the maximum allowable deviation in the axial direction is not more than 2mm, and the method of strong tightening bolts should not be used to eliminate skew. Tighten the bolts in two times, the first time evenly and symmetrically screwed once, and then tighten the bolts again.

 

FRP pipe connection requirements

When the interface works, the ambient temperature is not less than 10℃; the curing temperature after bonding is not less than 15℃, and the curing holding time is not less than 12 hours. Design the paste interface according to the laminate. According to the sample data, planned gel time, ambient temperature, etc., mix the resin and stir thoroughly. When the bonding thickness is more than 10mm, it should be formed in stages. Before each molding, the cured surface of the last molding should be polished.

 

Yongchang specializes in the production of various, FRP chemical storage tanks and FRP process tube can be customized! Ex-factory price, perfect after-sales service.