Polybutylene (PEX) have a brass or copper clamping ring.

Polybutylene (PEX) have a brass or copper clamping ring.

• A. Brass or Copper
• B. Plastic
• C. Steel
• D. Aluminum

Answer: (A)

The main idea is that PEX connections rely on a metal clamping ring that can be deformed by a crimp tool to grip both the tubing and the fitting, creating a tight, leak‑proof seal. Brass or copper rings are ideal because they are ductile and malleable, so the tool can compress them evenly without cracking the plastic or leaving gaps. They also resist corrosion in potable-water environments and are a well-established, compatible choice for PEX fittings. Other materials don’t fit well: plastic rings can’t be reliably crimped or hold their shape under pressure; steel rings may corrode and can be harder to crimp properly; aluminum rings aren’t standard for PEX and may not provide a durable seal.

The main idea is that PEX connections rely on a metal clamping ring that can be deformed by a crimp tool to grip both the tubing and the fitting, creating a tight, leak‑proof seal. Brass or copper rings are ideal because they are ductile and malleable, so the tool can compress them evenly without cracking the plastic or leaving gaps. They also resist corrosion in potable-water environments and are a well-established, compatible choice for PEX fittings. Other materials don’t fit well: plastic rings can’t be reliably crimped or hold their shape under pressure; steel rings may corrode and can be harder to crimp properly; aluminum rings aren’t standard for PEX and may not provide a durable seal.