ATCO portable heater made by Tecvalco Ltd.

The portable CWT Heater that Tecvalco Ltd. created for ATCO.

In 2016, ATCO was looking to develop a mobile regulating station (MRS). This is a portable heater that can be used to warm gas coming out of a compressed natural gas (CNG) tube trailer, wherever it may be. ATCO approached Tecvalco for help on this project.

Tecvalco’s first attempt was a single CWT 385 heater on a bumper pull trailer. The company manufactured and delivered two of these units to ATCO for testing. Initial testing found that while the heater worked well – and in fact supplied more than enough heat for the purpose – it ended up being too cumbersome. The unit required two separate trailers to take the equipment to site.

ATCO requested a design change to dual CWT 140 heaters on a single trailer with the hope they could still achieve the same result. The dual CWT 140 heaters were installed on a custom trailer in 2017, and have been operating successfully in the field since.

ATCO uses these trailers for a variety of purposes, such as bypassing stations while they are being upgraded, or for temporary supply during emergency outages.

The pressure of the gas on the CNG trailer is approximately 3,600 psi and, through multiple regulating stages, can be delivered out from the heaters at anywhere from 400 psi down to 14 psi. ATCO flows the gas through the first heater, where it goes through a regulator that reduces the pressure by half, and then into the second line heater before entering the second stage regulation.

In 2018, ATCO used the trailer to supply warm gas to a new outlet mall in Edmonton, as well as to the Edmonton international airport where repairs were completed on a transmission line. An ATCO technician noted that Tecvalco’s line heaters flowed 136,000 SCF per hour of warmed gas through the MRS supplying gas to the airport and the mall simultaneously.

ATCO deployed the system all over Alberta throughout the balance of 2018 with fantastic results, and are looking to purchase one or two more units in 2019.