Glass fiber reinforced plastic pipes have stable performance and corrosion resistance. Without external force damage, their service life can reach 30 years ( d on foreign experience, the performance has not changed after 50 years of use), so there will be no corrosion or perforation problems. The causes of damage to high-pressure fiberglass pipes are generally due to mechanical damage and other factors, and some are due to hidden dangers during construction, such as point loads caused by sharp stones, improper backfilling, and so on. Therefore, we can choose appropriate maintenance methods d on different damage situations.

1、 When there is a pinhole like leak in the pipe or the pipe is punctured by a sharp tool, the diameter of the damaged part does not exceed 20mm, and the working pressure of the pipe is below 3.5Mpa, it can be repaired by using a glass fiber reinforced plastic clamp for bonding

Step:

1. Clean up the damaged parts of the pipeline;

2. According to the size of the FRP clamp, polish the damaged parts and surrounding areas of the FRP pipe to expose a fresh surface;

3. Cut two pieces of polyester felt according to the size of the fiberglass clamp;

4. Completely soak the polyester felt with the prepared adhesive;

5. Apply adhesive evenly to the fresh surface of the polished fiberglass pipe and the inner surface of the fiberglass clamp;

6. Lay the soaked polyester felt on the fresh surface of the pipe, and then buckle the fiberglass clamp onto the polyester felt to make its inner surface coincide with the fiberglass. Fasten it with a steel clamp and brush the steel clamp with a of adhesive;

7. Remove excess adhesive and cure with an electric heating tape or baking gun.

2、 If the pipeline is severely damaged, it must be cut along the damaged part and bonded to the on-site threads. The following methods can be used for repair:

（1） Steel adapter maintenance: suitable for various forms of maintenance under various circumstances, the most common, fast maintenance; The steel adapter is a connected steel pipe hoop (double internal thread) and a rigid short joint (single external thread)

Material: 2 sets of corresponding steel adapters; 2 corresponding on-site threads; Adhesive 2 boxes; 1 box of sealing grease.

Step:

1. Cut off the damaged part of the pipeline;

2. After cutting, each of the two end faces of the pipe is bonded with a field thread;

3. Connect the steel adapter to the on-site thread;

4. Weld the steel adapter. If the welding length is insufficient (or too long), it can be fabricated on site;

5. Do a good job of anti-corrosion treatment for steel conversion joints and steel pipes, and carry out anti-corrosion treatment according to relevant requirements;

6. The thermal insulation pipeline shall be well protected from corrosion and heat preservation.

（2） Repair of short pipe and pipe clamp:

Material: 1-2 pipe clamps; 3-4 on-site threads; Adhesive 2 boxes; 1 box of sealing grease.

Step:

1. Cut off the damaged part of the pipeline;

2. Grind the two end faces of the cut pipe to match the taper of the on-site thread;

3. Prefabricate a short connection (double external threads) or short pipe (internal and external threads) by making on-site threads on site; At the same time, a field thread is adhered to the end surface of the polished taper pipe;

4. Put pipe clamps on both ends of the prefabricated short connection (if it is a short pipe, only one end can be used);

5. Screw the short connection through the pipe clamp (or short pipe) onto the on-site thread bonded to the pipe; Screw in the field thread on the pipe clamp at the other end of the short connection, and coat the inner cone surface of the field thread with adhesive;

6. Apply adhesive to the other polished outer conical surface of the pipe, and lift the pipe to socket connect with the adhesive coated on-site threads on the pipe collar;

7. Remove excess adhesive and heat to cure with a baking gun.

Note: This maintenance method is suitable for pipes that can be lifted and have good flexibility.

（3） Flange repair:

1. Cut off the damaged pipe sections, grind the cones on the remaining pipe sections and bond the on-site threads;

2. Install a piece of fiberglass flange on one side of the on-site thread;

3. Accurately measure the length of fiberglass short pipes with internal and external threads required for flange connections;

4. Connect the fiberglass short pipe to the other side of the site and then connect it to the flange. When connecting, be sure to pay attention to the position of the screw holes on the two pieces of fiberglass flange;

5. Align the two flanges, install the sealing gasket, and fasten the flange with bolts.