Company Announcement - Since transformers form such a large part of the asset cost structure of the power system, it is critical to their sustainability that the greatest care is taken in their manufacture or repair. LH Marthinusen’s Johannesburg transformer manufacturing and repair facilities needed to ensure that entrance to their winding shop was subjected to a controlled access process to guarantee the highest levels of cleanliness. Based on Apex Strip Curtains & Doors’ reputation and product offering, LH Marthinusen selected the SR 9000 heavy duty insulated impact traffic door. Apex delivered and installed the two double doors and two single doors in January 2014 after assessing the optimum solution for the facilities.

LH Marthinusen, a member of ACTOM (Pty) Ltd, is one of the largest global operations of its kind, offering a comprehensive suite of on- and off-site electro-mechanical repair and manufacturing services to all industry sectors. “LH Marthinusen’s reputation is built on the provision of high-quality products and services to a discerning customer base. Attention to quality forms the backbone of our operation and is underlined by our ISO 9001 certification,” says Corné Pretorius, electrical planner for large transformers at LH Marthinusen.

For the power generation industry, LH Marthinusen offers refurbishing of transformers ranging from 10 kVA to 200 MVA with voltages up to and including 132 kV. Pretorius points out that designs for transformers requiring new windings are checked and improved where necessary. New windings are insulated using either Kraft paper, thermally upgraded paper or Nomex, depending on customer requirements. The facility is also capable of designing and manufacturing power and distribution transformers up to 60 MVA at 132 kV, fitted with off-circuit or on-load tap changers. “By ensuring that the lowest possible amounts of dust and other contaminants enter the section where winding assembly takes place, we are able to improve transformer lifespan. Our existing barriers included wooden doors, which were unable to ensure the high levels of cleanliness we required. One of our larger clients regularly performs site inspections and the inclusion of superior quality heavy duty doors formed a focal point of our ongoing improvement programme to retain preferred supplier status,” he explains. The Apex SR 9000 doors are engineered to ensure the highest levels of safety and ruggedness, combined with the ability to manage the ingress of foreign matter. According to Wim Dessing, managing director of Apex Strip Curtains & Doors, it is important that traffic doors afford both functionality and longevity. “In this instance, LH Marthinusen required unimpeded traffic flow but with minimal transfer of dust and fibres from other areas within the facilities.”

Pretorius is particularly pleased with the durability provided by the bull nosed edge on the perimeter edges of the door. “The doors are subjected to a fair amount of knocks and bumps and have to date shown absolutely no signs of wear. This is an important factor, contributing to the reliability and longevity of the door, which in turn ensures that the environmental impact on the insulated winding facility is kept to a minimum over extended periods of time.” High bumpers are also fitted to the door panel to further absorb impact from forklift trucks and carts and reduce stress on hardware and mount assemblies. Pretorius says that another benefit provided by the Apex SR 9000 doors is their ease of operation, with automatic closure after they are opened. This is achieved by mounting the doors on an internal welded steel perimeter with corner gussets, using a CMI type ‘V’ gravity hinging system.

“We are extremely pleased with the performance of the Apex SR 9000 doors. Not only do they meet the stringent requirements of our internal quality auditing programme, but they also meet the demands of our client base,” Pretorius concludes.

SR 9000 DOOR AT LH MARTHINUSEN PICS 01 AND 02: Apex Strip Curtains & Doors delivered and installed two double and two single SR 9000 heavy duty insulated impact traffic doors at LH Marthinusen’s Johannesburg transformer manufacturing and repair facilities in January.

SR 9000 DOOR AT LH MARTHINUSEN PIC 03: LH Marthinusen required unimpeded traffic flow but with minimal transfer of dust and fibres from other areas within the facilities.