Selecting tractor-trailer air lines

Selecting tractor-trailer air lines

When selecting air lines for a tractor/trailer, the experts at Phillips Industries advise that they be chosen by following a list of certain features.

When selecting air lines for a tractor/trailer, the experts at Phillips Industries say it is recommended—and is sometimes required by law—to choose them with the following features:
• Airline assemblies that display the appropriate markings, which signify compliance with DOT regulations (required by law).
• Swivel fittings on the tractor end to avoid corkscrewing during installation.
• Spring guards to protect the hose or tubing from a sharp bend at or near the fitting.
• Added handle grips at the trailer end to provide protection from kinking of air lines during gladhand connection and disconnection.
• Coiled assemblies that extend to their maximum expected service length and return to their retracted position without sag.

However, the biggest factor is that proper overall working length should be used. In all cases, the length of the assembly must be adequate enough to ensure that the airlines are not stretched beyond a safe degree at their maximum expected service length, but must also be short enough to be protected from abrasion, snagging or tangling when in a relaxed state. To ensure that these standards are met, you must determine the proper length of the air assembly based on a number of factors.

These factors include the lead length, whether straight air lines or coiled assemblies are being used, the type of airline suspension method, and the positioning of the tractor/trailer when taking measurements.

According to SAE J702, the tractor connections on newer vehicles must be mounted low to allow easier access. This makes hook-ups more accessible but requires that the lines have a longer lead and some type of suspension system. Lead length is usually 12, 40, 48 or 72 in.; the most common is 48 in.

Lead length on the trailer side of the assembly should generally be between 6 and 12 in. Since the installation locations on trailers are usually very low, the use of leads that are longer than this will likely cause sagging of the lines.

After determining lead length, other factors need to be taken into consideration, although it should be noted that lead length does not necessarily always need to be determined first.

For more details on this two-part topic series, visit  www.phillipsind.com. Click through “Resources” to “Tech Tips.”

You May Also Like

HERE Technologies offers brand-specific search

This new capability is a further step in enabling HERE customers and partners to deliver differentiated services.

HERE Technologies recently announced a new platform capability available for global businesses to uniquely customize the search outcomes their users receive by using their own places of interest data. Powered by HERE Workspace and HERE Search, customers can add private data into the map and search function, creating brand-specific search outcomes and distinct end-user experiences.

Goodyear, Gatik demonstrate accurate tire-road friction potential estimate

The breakthrough will add more utility to what a tire can deliver by providing critical data that can help enhance vehicle safety.

Auto Value, Bumper to Bumper and All-Pro Truck Parts highlight Alliance Commercial Vehicle and Heavy-duty Program at HDAW

The Alliance looks toward continued growth in the medium- and heavy-duty aftermarket.

autovalue-1400
Photo Gallery: Heavy Duty Aftermarket Week 2023

A pictorial walk-around of the show floor.

welcome-to-hdaw-1400
Dayco expands heavy-duty diesel engine belt kit line

Six new SKUs join the 40-plus that Dayco has recently added.

Dayco-HD-HDAW-1400

Other Posts

Cummins-Meritor talks acquisition impact, aftermarket support

Here’s how the brands come together and do business in the market.

Cummins-Meritor-Alan-Rabadi-1400
HDAW 2023 general session talks through ‘unprecedented times’

The HDAW Expo floor is sold out, there 1,800 one-on-one meetings scheduled, and 756 distributors among the 2,500 attendees. It’s a big year.

HDAW-General-Session-1400
VIPAR Heavy Duty sponsors Northwood students at HDAW

The students will also have the opportunity to assist the VIPAR Heavy Duty team at their booth during the Product Expo.

HDAW-2023-Entrance
Bulldog HD showcases new, improved Steering Dampener at HDAW 2023

Find Bulldog HD at Booth #441, during HDAW ’23 in Grapevine, TX.

BULLDOG-HD-steering-1400