Piping rail

A piping is the edge reinforcement of a cloth or a tarpaulin , which is usually made of plastic or fabric-covered leather . The welt has a round cross-section and a wide, flat welt flap for fastening purposes . This represents the connection between the tarpaulin and the piping. The piping flag is usually a covering that contains the piping bead. The welt flap and tarpaulin are usually welded together, and rarely sewn. The part of the tensioning mechanism into which the keder is inserted is called the keder rail . This is a guide groove with a round cross-section, in which the piping can be inserted and moved lengthways without friction. The piping rail has areas where it can be picked up for the purpose of tensioning, for example. Piping and piping rail make it possible to stretch a tarpaulin (or a similar material) across the edge line across the entire surface.

Keder system using the example of a 22 mm × 50 mm variant

Detail definitions

Keder is called:

the manufacture of tarpaulins, e.g. For example: “Keder all around” fabric.
the pure piping bead.
(also casually while handling :) the entire edge of a tarpaulin designed in this way, e.g. For example: "... please insert the piping ..." What is meant is - because it is connected to each other - "piping plus piping covering plus piping flag plus tarpaulin".

When specifying dimensions for tarpaulins made up of piping, it makes sense to clarify the terms together beforehand. The following should be clarified:

Is the "piping diameter" the ...

Diameter of the (mostly plastic) welt bead or
the keder bead including keder coating?

Is the "tarpaulin dimension" the dimension ...

the actual tarpaulin (without piping parts),
the tarpaulin from piping inside to piping inside,
the tarpaulin from piping outside to piping outside or around
the clear dimension from one keder rail to the other in the tensioned / untensioned state?

use

The piping rail is used professionally in outdoor advertising and in modern tent construction as well as for presentation areas, for example in trade fair construction . Even big screens for film projection are often placed in this procedure. The piping rail must be dimensioned and attached in such a way that the tensile forces that occur deform it as little as possible, otherwise undesirable wrinkles will form in the tarpaulin .

Large tents : In the construction of large tents, there are fixed or integrated piping rails on the gable crossbars, into which the piping of the roof segments is inserted. The segments are then pulled over the ridge to the other side of the tent by a pulling device .

Large-area advertising: For large-area advertising, the piping rail (usually made of aluminum ) is used to define the span level at least on one edge. Either on free-standing structures or on house walls to compensate for unevenness. The tension can also be made from the remaining sides of the tarpaulin using eyelets in the tarpaulin and tensioning ropes.
With keder tensioning frame systems, keder rails are used on all sides of the tarpaulin and clamping mechanisms are used on at least 2 sides. Tenter frames can be made watertight, especially in backlit systems, in order to protect the electrical parts ( fluorescent tubes and ballasts) behind them from water ingress.

Camping and caravanning

Piping rail on the caravan

Awning: A continuous piping rail is located on each caravan on the roof edge on the door side. It is used to hold the piping, which is sewn onto the awning or sun roof, and connects it firmly to the vehicle. The length of the piping rail determines the "circumferential dimension", which in turn determines the size of the awning or sun canopy. If the piping rail length and circumferential dimensions do not match, the tent or sun canopy either folds (too long) or the awning floats in the air and the mud flap does not touch the ground (too short).

Awnings and wind protection: More piping rails are mounted on trailer via the opening windows to awnings collect, and along the door-side lower edge of the vehicle, in order to attach a windshield.

Double rail : In addition to the keder rail that is permanently mounted on the car, you also know the double keder rail made of plastic (to be bought by the meter) when camping . B. is used to connect the main tent with an alcove tent rainproof or to attach rain gutters to the edge of the tent roof.

The term “piping” in other contexts

Sailboat: In many sailboats , the luff and foot of main sails are guided in a groove ("keep") on the mast or tree with the help of their thickened edges on the canvas - similar to the guidance of tarpaulins in piping rails. The thickening is usually not achieved with sewn-on piping, but with sewn-in ropes ("Liektaue").

Vehicle construction: In motor vehicles, the rubber seals that are placed around the doors or between the fenders and the body (on the VW Beetle) are called rubber piping . The windshields of older models were usually sealed with rubber piping (without piping rail).

Upholstered furniture: In the manufacture of upholstered furniture, a piping is used both to cover and decorate seams and to reinforce edges. Piping is used as a decorative element (without piping rail) when covering upholstered furniture, for example. Strictly speaking, this is a piping . The piping core is the inner part of the piping.

Loudspeaker boxes : With loudspeaker housings, especially guitar boxes and combo amplifiers, a piping tape is used between the front panel (baffle board) and the side walls to reduce vibrations and to maintain the central alignment. See Marshallbox .

Knife sheath: In order to prevent the seam from being cut when pulling or inserting the knife and to protect against piercing, a quiver sheath (usually made of leather) is placed between the halves to be sewn.

Window construction: The rubber hose with which the mosquito net is pressed into a suitable recess in the frame and thus fixed is also called rubber piping .