scope:

This publication contains guidelines for the use of CGA-341 and TC-341 cryogenic trailers when moved in either direction between the United States and Canada. These trailers are typically used to transport the following cryogenic liquids at pressures less than 25.3 psi (174.4 kPa) although the maximum allowable working pressures of CGA-341 and TC-341 trailers are between 25.3 psi and 150 psi (174.4 kPa and 1034.2 kPa): ^{1, 2}

• oxygen;

• helium;

• nitrogen; and

• argon.

Noncryogenic trailers such as gas tube trailers are not covered in this publication.

Purpose

This publication also provides guidance on determining if the trailers conform to U.S. and Canadian regulatory requirements [2, 3, 4, 5]. These requirements include trailer design, year of manufacture, requalification, and maintenance.

This publication provides guidance for the following fill and deliver scenarios:

• trailer is filled in the United States and delivers cryogenic liquid to a customer in the United States;

• trailer is filled in the United States and delivers cryogenic liquid to a customer in Canada;

• trailer is filled in Canada and delivers cryogenic liquid to a customer in Canada; and

• trailer is filled in Canada and delivers cryogenic liquid to a customer in the United States.

¹ kPa shall indicate gauge pressure unless otherwise noted a (kPa, abs) for absolute pressure or (kPa, differential) for differential pressure. All kPa values are rounded off per CGA P-11, Guideline for Metric Practice in the Compressed Gas Industry [1].

² References are shown by bracketed numbers and are listed in order of appearance in the reference section.