PPb Pipe Fittings Metric

Our polypropylene (PP) plain fittings range is designed for demanding industrial environments where chemical resistance, thermal stability and long-term reliability are essential. Manufactured from beige-grey polypropylene block copolymer (PP-B), these fittings form part of a robust, precision-engineered system suitable for conveying aggressive and high-temperature media across a wide variety of industries.

Polypropylene is a modern thermoplastic that combines strength, durability and excellent chemical resistance with a lightweight construction, making it a highly cost-effective choice for industrial pipeline installations. Its non-toxic, food-grade properties also allow it to be safely used in sensitive applications such as food processing, pharmaceutical production and laboratory environments.

All metric pressure polypropylene fittings in this category are produced from PP-B (block copolymer) in beige grey (RAL 7032) and manufactured in accordance with recognised international standards, ensuring dimensional accuracy, consistent quality and dependable performance:

• DIN 16962 (Parts 5/6/7/8/9/12)
• ISO 7279:1984
• ISO 15494:2003 Type B
• Quality and testing regimes to DIN 16962-5 and ISO 15494:2003

Polypropylene exists in several forms, each offering different performance characteristics:

• Homopolymer PP (PP-H) - high rigidity but reduced impact resistance at low temperatures
• Beta-nucleated homopolymers - improved impact strength
• Block copolymer PP (PP-B) - superior impact resistance, particularly in cold conditions

Chemflo polypropylene fittings are manufactured from high heat-stabilised PP-B, delivering:

• Excellent impact resistance at sub-zero temperatures
• Strong chemical resistance
• Reliable performance across a wide temperature range

This makes PP-B especially suitable for industrial pipework where durability, flexibility and safety are critical.

• Smooth Bore
  • The smooth internal surface minimises friction losses, enabling high flow rates and reduced pressure drop
• Ductility & Flexibility
  • Under overload, PP fittings can deform and return to their original shape once the load is removed. This allows them to absorb ground movement when buried and makes installation adjustments easier. Pipes can be cold-pulled to bends of up to 50 × outside pipe diameter
• Maintenance-Free
  • Polypropylene does not corrode, rot or degrade, even when buried underground or cast into concrete
• Lightweight
  • With a lower density than many thermoplastics, polypropylene is easy to handle and install, reducing labour time and installation costs
• Thermal Insulation
  • As a poor conductor of heat, polypropylene significantly reduces external condensation compared to metal pipe systems
• UV Resistance
  • Beige-grey polypropylene offers good resistance to sunlight and is suitable for outdoor use in the UK. (Natural/unpigmented PP is not suitable for outdoor exposure)
• Temperature Resistance
  • Continuous operating range: -20°C to 110°C
  • Short-term steam sterilisation: up to 130°C
• Impact & Wear Resistance
  • Excellent resistance to impact damage during handling and installation, with abrasion resistance superior to many other thermoplastics - ideal for slurry and particulate media

Polypropylene is widely recognised for its exceptional resistance to chemical attack, particularly in aggressive industrial environments:

• Extremely high resistance to water and inorganic environments
• Water absorption as low as 0.03% after 24 hours (ASTM D570-63)
• Resistant to most strong mineral acids and bases
• Minimal weight change after prolonged exposure to aqueous solutions

While polypropylene performs exceptionally well with most chemicals, strong oxidising agents at elevated temperatures can cause degradation. For applications involving aggressive oxidisers or unusual chemical combinations, technical guidance is always recommended.

Socket fusion (also known as polyfusion) is a heat-welding process where the outside of the pipe and the inside of the fitting socket are heated simultaneously using a dedicated fusion tool. Once softened, the components are pushed together to form a permanent, leak-free joint.

The welded joint becomes as strong as the pipe itself, with no seals, adhesives or mechanical fasteners required.

To achieve a reliable socket fusion joint, you will need:

• Socket fusion welding machine (polyfusion tool)
• Correct heater bushes and spigots for the pipe size
• Pipe cutter or fine-tooth saw (square cut)
• Deburring / chamfering tool
• Marker pen or depth gauge
• Clean lint-free cloth
• PPE: heat-resistant gloves and eye protection

Important: Always use heater bushes that exactly match the pipe and fitting size. Incorrect sizing is the most common cause of failed joints.

• Fusion tool temperature: 260°C ±10°C
• Allow the tool to fully stabilise before welding
• Never weld below temperature or with contaminated heater surfaces

1. Cut the Pipe Square

• Cut the PP pipe cleanly and square to ensure full, even contact inside the fitting socket

2. Chamfer and Clean

• Lightly chamfer the pipe end to ease insertion
• Remove burrs and debris
• Wipe both pipe and fitting with a clean, dry cloth
• Cleanliness is critical - dirt or moisture will weaken the weld.

3. Mark the Insertion Depth

• Insert the pipe into the fitting without heat and mark the insertion depth on the pipe using a marker pen
• This prevents over-insertion during welding, which can restrict bore diameter

4. Heat the Components

• Place the pipe onto the external heater spigot
• Place the fitting onto the internal heater socket
• Apply firm, even pressure only - do not twist
• Always follow the manufacturer’s time chart for your welding machine

5. Remove and Join Immediately

• Remove pipe and fitting simultaneously
• Push the pipe straight into the fitting up to the depth mark
• Do not twist or rotate
• Hold firmly in position

6. Cooling Time

• Hold joint steady for 10 - 30 seconds (size dependent)
• Allow full cooling before applying stress or pressure
• Do not accelerate cooling with water or air

Polypropylene plain fittings are widely used across industries requiring clean, durable and chemically resistant pipework, including:

• Chemical processing and storage
• Pharmaceutical and biotechnology facilities
• Hospitals and laboratory drainage systems
• Water treatment and de-ionised water systems
• Brewing, distilling and food production
• Electronics manufacturing
• Effluent and waste treatment plants
• Ultra-pure water and process pipelines

Common conveyed media include acids, alkalis, alcohols, brines, solvents, plating solutions, sugar solutions, slurries and more.