PE-RT/AL/PE-RT piping is produced in various sizing schemes for a variety of applications including air conditioning line sets and refrigeration piping. Certain PE-RT/AL/PE-RT pipes are also intended for hydronic applications such as radiant heating and snow & ice melting as well as select gases (e.g., nitrogen, compressed air) which are compatible with the specific piping material. PE-RT/AL/PE-RT piping is a flexible piping material that is typically sold in coils.

Definition

PE-RT/AL/PE-RT piping is a coextruded composite pressure pipe with a welded aluminum tube reinforcement between the inner and outer layers. The inner and outer polymer layers are bonded to the aluminum tube by a melt adhesive. PE-RT is a polyethylene (PE) resin in which the molecular architecture has been designed such that a sufficient number of tie chains are incorporated to allow operation at elevated or raised temperatures (RT). Tie chains "tie" together the crystalline structures in the polymer, resulting in improved properties such as elevated temperature strength and performance, chemical resistance, and resistance to slow crack growth.

Overview

PE-RT/AL/PE-RT piping is a high-temperature flexible plastic pressure pipe produced in different size ranges for specific applications.
 
Pipes produced according to ASTM F3346 are labelled as diameter nominal (DN) sizes from 12 to 32. These nominal diameters match the minimum outside diameter measured in mm. Pipes produced according to ASTM F3346 have a minimum pressure design basis (PDB) rating of 400 psi at 23ºF (2.76 MPa at 73ºC) and 200 psi at 180ºF (1.38 MPa at 82ºC). ASTM F3346 requires that all such PE-RT/AL/PE-RT pipe designed to be used with refrigerant shall be tested for compatibility with each refrigerant as specified by the manufacturer.
 
Pipes produced according to ASTM F3506 are labelled as nominal sizes from 1/4 to 1 1/8 and are ID controlled to match that of ACR copper tube so that the flowrate and volume remains the same on a size-for-size basis. Pipes produced according to ASTM F3506 have a minimum pressure design basis (PDB) rating of 400 psi at 23ºF (2.76 MPa at 73ºC) and 200 psi at 180ºF (1.38 MPa at 82ºC). ASTM F3506 requires that all such PE-RT/AL/PE-RT pipe designed to be used with refrigerant shall be tested for compatibility with each refrigerant as specified by the manufacturer
 
Consult the specific PE-RT/AL/PE-RT piping manufacturers' literature and listings for appropriate pressure ratings.

PE-RT/AL/PE-RT Advantages

• Ease of installation, easy to bend
• Lightweight, compact, easy to transport
• Flexibility combined with stiffness to hold its shape
• Aluminum layer prevents refrigerant from permeating into pipe
• No flame used for joining, reduced fire risk
• Reduced number of fittings and joints, reduced leakage
• Durability and toughness to survive jobsite installations
• No copper content which reduces chance of theft

PE-RT/AL/PE-RT Applications

• Air conditioning line sets and refrigeration (ACR) - ASTM F3346 and F3506
• Radiant heating and cooling systems – ASTM F3346
• Hydronic piping and distribution – ASTM F3346
• Turf conditioning/pitch heating – ASTM F3346
• Outdoor snow and ice melting – ASTM F3346
• Chilled water piping – ASTM F3346

PPI Members with PE-RT/AL/PE-RT Systems

• Yoga Pipe
• Gastite Python

Most Relevant PE-RT/AL/PE-RT Standards

• ASTM F3346 - Standard Specification for Polyethylene of Raised Temperature/Aluminum/Polyethylene of Raised Temperature (PERT/AL/PE-RT) Composite Pressure Pipe
• ASTM F3506 - Standard Specification for Standard Specification for Polyethylene of Raised Temperature/Aluminum/Polyethylene of Raised Temperature (PE-RT/AL/PE-RT) Composite Pressure Pipe based on Inner Diameter (ID) for use in Air Conditioning and Refrigeration Line Set Systems