General Specification 
Door Curtain 
The curtain is made from prime galvanised Z2 quality mild steel 0.5mm thick into 915mm deep panels, which are lockseamed together to form a continuous curtain. (The strength of the door in the horizontal direction is derived from the design and depth of the profile, and not the thickness of the steel.) Finish is either plain hot dipped galvanised, or a range of colours in Plastisol colour coat. 
Edging System 
The curtain is fitted with a very hard wearing nylofelt edging strip stapled on both sides of the door. On door heights which exceed 3300mm this is reinforced with a stainless steel edging strip. Nylofelt is a PVC core extrusion covered with a woven nylon fabric, providing a dry bearing surface, which requires no greasing of the door guides. 
Door Drum 
The door drum is fabricated around specially designed drum wheels 3mm thick, which are fitted with nylon bearings. On electric operated doors oilite bearings are used on both outer drums. The drum rotates around the fixed centre axle. 
The axle is a galvanised steel tube – 25mm bore BS1387 Heavy Duty. 
Bottom Rail 
The bottom rail is an L – section aluminium extrusion lock seamed to the bottom panel of the door, to which is fitted a PVC ribbed tubular weather skirt. 
Balance Springs 
The doors are assisted with specially designed torsion springs, of various gauges and lengths, to suit door size. 
Guides Channels 
Guide channels are galvanised roll form U sections 2.5mm thick – 50mm; 63mm; 75mm deep according to door size. Galvanised fixing angles are spotwelded according to installation application. 
Chain Operation 
The hand chain is galvanised mild steel calibrated chain which drives a glass reinforced nylon planetary gear set providing a reduction of 3.5:1, and runs through a pressed galvanised chain guide fitted with nylon inserts. 
Electric Operation 
Electrically operated doors are supplied with half HP motor. Pre-wired with low voltage cables to a 3 push button control at the low level and a 16amp 5-pin plug at the high level. Gear driven travel limits are contained within the starter enclosure. Emergency opening and closing is via floor level controlled haul chain. 
Each door is normally fitted with a waist high shoot bolt, which is zinc plated and specifically designed to fit the door profile. They are conveniently at waist height and are padlockable. The hand chain is also padlockable in 4mm thick plated steel chain keep. No lock is normally supplied on electrically operated doors. 
Designed and created by it'seeze