A recent inquiry from a CAAR member brought this issue to our attention. There has been some questions about the correct interpretation of the rear end protection (bumper) requirements for TC51 tanks in the CSA B620 and B622 Standards. The clarification on the issue is detailed below.

Situation:

• The dealer had purchased several new 2,000 USWG (7,600 litre) TC51 tanks made by Propar and Maxfield in 2020 and 2021.
• The tanks are mounted on Duolift and Maxfield agricultural wagons similar in style to the wagons used for the non spec nurse tanks. The rear end protection for the tank did not meet the requirements of the CSA B620 standard as there was no engineered rear end protection (bumpers) on any of the TC51 tanks and wagons in question.
• A TC audit cited the dealer for not having adequate rear end protection.

Interpretation of CSA B620 and B622 on this issue:

• Section 5.2.5 of CSA B620 requires that a TC51 tank that is loaded or unloaded without being removed from the running gear, must be completely contained within the length of the vehicle to which it is attached.
• This requires rear end protection (rear bumper) which must be designed and certified according to Section 5.1.5.4 of the CSA Standard by a Professional Engineer.
• The rear end protection (bumper) must be able to deflect horizontally forward a minimum of 6” or 15 cm without any contact with any part of the tank.
• The fabrication of the rear end protection (bumper) and mounting the rear end protection (bumper) can be done by a local welding shop using and adhering to the STAMPED engineered plans for the rear end protection (bumper).
• Any tank made after Jan 12, 2018, that is selected for use with anhydrous ammonia must be a TC51 specification tank and meet all the associated requirements.

Glenn Dickson, P.Ag
CSA B620 member
April 4, 2025