UPVC pipe installation operation specification

UPVC pipe connection method selection and precautions

1. Connection method selection principle

• Pipe diameter and pressure:

• When the pipe diameter is ≤160mm, bonding (adhesive) connection is preferred; when the pipe diameter is ≥63mm, elastic sealing ring connection or flange connection can be used.

• Socket rubber ring or flange connection is recommended for high-pressure scenarios, and flexible interface can be used for low-pressure drainage systems.

• Environmental adaptability:

• In chemical corrosion environments, the sealing ring must be corrosion-resistant (such as Shore hardness 45-55 degrees);

• Avoid construction when the temperature is below 5℃, or use thick-walled pipes/MPVC pipes to improve brittleness resistance. 

2. General precautions

• Cleaning requirements:

Before connection, use acetone or special cleaning agent to thoroughly remove oil, dust and water stains on the inside of the socket and the outside of the plug, otherwise the bonding strength will be reduced.

• Environmental control:

• The construction temperature should be between 10-25℃, and antifreeze measures should be taken if the temperature is below -10℃;

• High temperature (>40℃) will accelerate the volatilization of the adhesive, resulting in "solvent rupture".

• Sealing guarantee:

• The elastic sealing ring must be complete and free of cracks, avoid twisting during installation, and can be lubricated with soapy water;

• After bonding, it needs to be left to solidify (the time depends on the performance of the adhesive), and the pipe is prohibited from moving during this period.

Detailed explanation of the core connection method

1. Socket-type bonding connection (applicable to pipe diameter ≤160mm)

Steps: Pipe end treatment:

• The fracture is flush, the outer edge is milled with a 10°-30° chamfer, and the thickness of the chamfer tip is ≥1/3 of the wall thickness.

• Measure the socket depth (L) and mark the insertion position at the spigot end (L1=3/4L).

2. Test insertion and cleaning:

• Test insertion to 3/4 of the marked depth and check the fit clearance;

• Use sandpaper to roughen the bonding surface horizontally and remove oil with acetone.

3. Glue application and insertion:

• Apply glue to the inside of the socket first, then to the outside of the plug (within the L range), and apply glue evenly to avoid excessive glue;

• Insert to the marked depth in 20-30 seconds at a time, and rotate 90° to make the glue evenly distributed.

4. Curing: Remove excess adhesive and let it stand until it cures (usually 30 seconds for initial fixation).

Elastic sealing ring connection (applicable to pipe diameter ≥63mm)

Steps:

1. Sealing ring installation: Insert the sealing ring correctly into the sleeve groove to avoid twisting.

2. Pipe end lubrication: Apply soapy water to the sealing ring and pipe end for lubrication.

3. Insertion control:

• The insertion depth is 10-20mm shorter than the socket;

• Large-diameter pipes can be tapped with a mallet or tightened with a tensioner.

3. Electrofusion connection (applicable to large-diameter or high-demand scenarios)

Steps:

1. Pipe end processing: Cut flat, sandpaper polish to remove burrs.

2. Pipe fitting installation: The electrofusion pipe fitting is inserted into the pipe end to ensure complete fit.

3. Electric melting: 

• Connect the power supply and heat for 60-120 seconds until the electric fuse is completely melted.

4. Cooling and inspection: 

• Natural cooling for 5-10 minutes, check for leakage and deformation before use.

Key control points for sealing

1. Adhesive sealing:

• The adhesive must cover the entire bonding surface, and even overflow of the glue after insertion indicates a good seal;

• Insufficient glue (discontinuous overflow) or excessive glue (flowing) requires rework.

2. Sealing ring installation:

• The sealing ring must not be displaced after installation, and large-diameter pipes must be verified by water pressure test.

Pressure test standards

1. Test timing:

• Adhesive connection: 24-48 hours after installation;

• Elastic sealing ring connection: after filling with sand/soil.

2. Test method:

• Test pressure ≥ 1.5 times the working pressure (and ≥ 0.6MPa);

• Slowly pressurize (pressurization ≥ 10 minutes), stabilize the pressure for 1 hour, and the pressure drop is ≤ 0.05MPa/15 minutes to be qualified.

Special scene processing

1. Temperature change compensation:

• Calculation formula: △L = L·α·△t (α is the linear expansion coefficient);

• When the temperature difference in the north is large, expansion joints (spacing ≤ 4m) are required.

2. Chemical environment:

• Flange connection is preferred, and bolts are tightened symmetrically;

• Rubber rings must be corrosion-resistant (aging coefficient> 0.8).

Safety and quality assurance

• Tool specifications: Use special chamfering tools, sandpaper (below 400 mesh) and adhesive brushes;

• Safety protection: Wear gloves and goggles during operation, and open flames are prohibited during on-site ventilation (adhesives are flammable);

• Acceptance criteria: No leakage or deformation at the interface, and the bracket spacing meets the design requirements (anti-settlement).

UPVC pipe connections must be selected based on the pipe diameter, pressure, and environment, and strict cleaning, temperature control, sealing operations, and pressure testing must be performed to ensure long-term stable operation of the system. During construction, it is necessary to focus on preventing adhesive volatilization, sealing ring distortion, and temperature stress problems, and follow the manufacturer's technical guidelines.

FAQ

Q1: What is the difference between UPVC and MPVC pipes?

A: UPVC (Unplasticized Polyvinyl Chloride) pipes are rigid and widely used due to their corrosion resistance and low cost. MPVC (Modified PVC) pipes have improved impact resistance and toughness, making them better suited for environments with temperature fluctuations or minor ground movement.

Q2: When should electrofusion pipe fittings be used in irrigation systems?

A: Electrofusion fittings are ideal for high-pressure polyethylene (PE) pipe connections, especially in areas with soft soil or seismic activity, where strong, leak-proof joints are essential.

Q3: Are UPVC pipes suitable for highly corrosive soil conditions?

A: Yes, UPVC pipes have excellent chemical resistance and are well-suited for use in highly corrosive soils without requiring additional anti-corrosion treatment.

Q4: What type of pipe is recommended for soft soil foundations?

A: PE pipes are typically preferred due to their flexibility and ability to accommodate foundation settlement. MPVC can also be considered if improved toughness is required.

Q5: Can electrofusion fittings be used with UPVC or MPVC pipes?

A: No, electrofusion fittings are specifically designed for PE pipes. UPVC and MPVC pipes typically use solvent welding or rubber ring connections instead.