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What types of equipment are there?

 

Main principles

Continuous flow v pressure demand

Types of respirators

Accessories to consider

Main principles

If you have to work in an area in which the air cannot be filtered, only one solution remains: you have to have clean air supplied to you. This can be done in two main ways:

  • You take the air with you (portable systems)
  • You connect to a permanent air supply through a hose (fixed systems)

Portable systems can in turn be divided into two types:

  • Small air cylinder carried on the person (self-contained breathing apparatus)
  • Large air cylinder wheeled on a cart or trolley

Fixed systems, on the other hand, are usually supplied by a compressor, pumping clean air into a holding tank.

There are pros and cons with portable and fixed systems alike. Carrying air with you, whether on your back or on a cart, means limited operatying duration and often heavy loads to move around. Fixed systems give you unlimited operating time, but your movements are restricted because you are always connected to an air outlet through a length of hose.
IMPORTANT DIFFERENCE: if you are using a compressed air cylinder (above, right), it is important that your respirator is of the tight-fitting face-seal type, and that it features a PRESSURE DEMAND VALVE (see below), that is, a valve that ensures that air is released from the cylinder only when you breathe in. Otherwise, the air will escape just like water rushing out of a a fully opened tap, and the cylinder will be empty within a very short time. On the other hand, if you use an air compressor (above, left), you can use non-demand valve respirators as an alternative, as well as loose-fitting hoods and shields.

 
Continuous flow versus pressure demand

CONTINUOUS FLOW means an uninterrupted, unchanging air flow to the respirator. Even when you breathe out or hold your breath, the same air supply is delivered to the respirator. This principle is suitable for hoods, shields, helmets and other loose-fitting respirators, coupled with a constantly working compressor.

PRESSURE DEMAND essentially means that air is only delivered when you breathe in. A sensitive valve senses when you start to inhale and opens the air supply. The moment you stop inhaling, the air supply is shut off. This principle is suitable for tight-fitting face masks connected to either a compressor or cylinder.

 
Types of respirators
Fixed systems:    
Hoods

Supplied air hoods come in various materials and designs. Some have special uses, such as welding.

For hoods offered by S.E.A., click on the picture.

Shields

Supplied air shields can be of a helmet type with a flip-up visor

For shields offered by S.E.A., click on the picture.

Tight-fitting half and full face masks with supplied air adaptors

Some conventional filter respirators can be easily converted to accept supplied air.

For products offered by S.E.A., click on the picture.

Tight-fitting half and full face masks with fitted airline (with or without back-up filter)

Tight-fitting half and full face masks with permanent supplied-air connections.

For products offered by S.E.A., click on the picture.

Portable systems:    
Self-contained

Air cylinders carried on a harness.

Call S.E.A. for more information.

Cylinder trolleys

Handy carts for several cylinders.

Call S.E.A. for more information.

 
Accessories to consider
Voice communication

Voice communication can be difficult to obtain in supplied-air respirators, as the air flow may interfere with sound transmission. Solutions include mechanical speech diaphragms and electronic systems.

For voice communication systems offered by S.E.A., click on the picture.

Back-up filters Some supplied air systems can be fitted with back-up filters that let you escape the area safely if the air supply is accidentally interrupted. Contact S.E.A. for possible solutions.
Back-up cylinders Short-term back-up cylinders of air may be connected to some systems. Contact S.E.A. for possible solutions.l