background image

PAS

®

 ASV

Automatic switch-over valve

Instructions for Use

i

PSS

®

 and PAS

®

 are trademarks of Dräger

3354242 (A3-D-P)

1

For your safety

1.1

General safety statements

Before using this product, carefully read the Instructions for

Use.

Strictly follow the Instructions for Use. The user must fully

understand and strictly observe the instructions. Use the

product only for the purposes specified in the Intended Use

section of this document.

Do not dispose of the Instructions for Use. Ensure that they are

retained and appropriately used by the product user.

Only fully trained and competent users are permitted to use

this product.

Comply with all local and national rules and regulations

associated with this product.

Only trained and competent personnel are permitted to

inspect, repair and service the product. Dräger recommends a

Dräger service contract for all maintenance activities and that

all repairs are carried out by Dräger.

Properly trained service personnel must inspect and service

this product as detailed in the Maintenance section of this

document.

Use only genuine Dräger spare parts and accessories, or the

proper functioning of the product may be impaired.

Do not use a faulty or incomplete product, and do not modify

the product.

Notify Dräger in the event of any component fault or failure.

The air supply shall meet the requirements for breathing air

according to EN12021.

1.2

Definitions of alert icons

Alert icons are used in this document to provide and highlight text

that requires a greater awareness by the user. A definition of the

meaning of each icon is as follows:

WARNING

Indicates a potentially hazardous situation which, if not

avoided, could result in death or serious injury.

CAUTION

Indicates a potentially hazardous situation which, if not

avoided, could result in physical injury or damage to the

product or environment. It may also be used to alert against

unsafe practices.

NOTICE

Indicates additional information on how to use the product.

2

Description

2.1

Product overview

The Dräger PAS

®

 ASV is an accessory that allows a Dräger self-

contained breathing apparatus (SCBA) to be used with an external

air source such as a factory airline or other breathing air supply

(e.g. Dräger PAS

®

 AirPack). The PAS

®

 ASV  automatically

switches between the external air source and the breathing

apparatus air cylinder, maintaining an uninterrupted air supply to

the wearer during switching.

2.1.1

Operation

During airline use, the PAS

®

 ASV uses the external air source as

the primary supply of breathing air to the wearer, and the breathing

apparatus air cylinder as the secondary (or back-up) supply. If the

external air source pressure remains above a preset pressure the

wearer breathes from the external air source.

If the external air source pressure drops below the preset

switching level, the PAS

®

 ASV switches to supply the wearer from

the breathing apparatus air cylinder. The low-pressure whistle

sounds to inform the wearer that breathing air is supplied from the

air cylinder:

If the external air source pressure recovers (increases above

the preset switching level) the PAS

®

 ASV switches back to the

external air source and the whistle stops.

If the external air source falls to atmospheric pressure or is

disconnected the whistle stops. The wearer continues to

breathe from the breathing apparatus air cylinder, and the

breathing apparatus operates as a self-contained set.

2.1.2

Component description

Automatic switch-over valve (Fig 1):

AL (airline)

Input from an external air source.

BA (breathing apparatus)

Input 

from 

the 

breathing

apparatus air cylinder.

LDV (lung demand valve)

Output to the lung demand valve.

Belt manifold (Fig 2):

Item 1

Male quick-coupling: an input coupling for connection to

an external air source. This coupling is not available on

some chemical protection suit (CPS) variants.

Item 2

Low-pressure whistle.

Item 3

Female  quick-coupling:  an  input/output  coupling  for

connection to the pass-through connection of a

chemical protection suit (CPS) or suit ventilation

device. The coupling is optional and is blanked on some

variants.

The PAS

®

 ASV is a permanent or occasional unit:

Permanent unit (Fig 3) – the belt manifold has a clamp for

permanent connection on to the apparatus.

!

!

i

i

Occasional unit (Fig 4) – the belt manifold has a removable clip (S-

type clip shown) that can be removed or installed when required

for specific operations.

The PAS

®

 ASV can be factory fitted or supplied as a kit. When the

PAS

®

 ASV is supplied as a kit the procedure for fitting is described

in the assembly instructions supplied with the kit.

2.2

Intended use

The Dräger PAS

®

 ASV provides an automatic switching function

to allow a Dräger self-contained breathing apparatus (SCBA) to be

used with an external air source to provide extended operating

time in a contaminated or oxygen deficient work area. The

PAS

®

 ASV  is  used  on  Dräger  PSS

®

, PAS

®

, and Plus Series

breathing apparatus.

2.3

Approvals

The European standards, guidelines, and directives according to

which this product is approved are specified in the declaration of

conformity (see declaration of conformity or www.draeger.com/

product-certificates).

2.4

Equipment marking

The labels on the PAS

®

 ASV cover are described in Section 2.1.2.

The equipment label under the cover shows the following

information (examples only):

BRAC-1359

Dräger serial number

3354XXX

Dräger part number

3

Use

3.1

Prerequisites

Refer also to the Instructions for Use supplied with the Dräger self-

contained breathing apparatus.

3.1.1

External air source

WARNING

The air supply shall meet the requirements for breathing air

according to EN12021. Do not use oxygen or oxygen

enriched air.
The input pressure from an external air source must not

exceed 10 bar. Higher pressures may cause breathing

difficulties for the breathing apparatus wearer.

The external air source shall provide:

Supply pressure: 6 bar to 10 bar

Supply flow rate: at least 550 litres/minute

3.2

Preparation for use

WARNING

The following procedures include system checks and the

acceptable test standards. Contact Dräger if the apparatus

fails to meet any of the standards or any audible air leak

can not be rectified.

NOTICE

The high-pressure whistle referred to below is the

breathing apparatus end-of service time alarm. It can be a

mechanical whistle or an electronic sounder depending on

the breathing apparatus type.

A trained and competent person must perform the following

preparation for use checks after assembly of an automatic switch-

over valve and each time before release of the equipment for

operational use to a wearer.

1. Install the air cylinder.

2. Connect the lung demand valve to the breathing apparatus.

3. Press the reset button on the lung demand valve (positive-

pressure only).

4. Open the cylinder valve. The high-pressure whistle will

momentarily sound.

5. Close the cylinder valve and carry out the functional testing

(leak test and whistle warning test) as detailed in the breathing

apparatus Instructions for Use.

6. Press the reset button on the lung demand valve (positive-

pressure only).

7. Open the cylinder valve of the breathing apparatus.

8. Open the valve of the external air source to pressurize the

system.

9. Connect the external air source to the male coupling on the belt

manifold. The low-pressure whistle will briefly sound, indicating

that the system has switched to use the external air source.

10. Check for audible air leaks.

WARNING

Do not direct the air flow on to the face, eyes or skin.

Pressurized air flow can cause serious injuries.

11. Firmly press the centre of the rubber cover of the lung demand

valve to activate the air flow for 3 to 5 seconds. Press the reset

button on the lung demand valve (positive-pressure only) to

stop the flow.

Standard:

 An unobstructed air flow will vent from the outlet of

the lung demand valve. The breathing apparatus pressure

reading should not change, indicating that the air is supplied by

the external air source.

12. Disconnect the external air source from the belt manifold.

13. Check for audible air leaks.

14. Close the cylinder valve.

15. Test the low-pressure whistle and automatic switch-over valve

as follows: 

a. Positive-pressure lung demand valve – Cover and seal the

outlet of the lung demand valve with the ball of the hand.

Press the centre of the rubber cover to switch on the valve

and then carefully lift the hand to slowly vent the air.

b. Negative-pressure lung demand valve – Carefully press

the centre of the rubber cover to slowly vent the air.

Standard:

 The low-pressure whistle will sound briefly at the

preset pressure (3.5 bar to 5.5 bar), and will decay as trapped

air in the airline hose falls to zero. The breathing apparatus

pressure reading should decrease, indicating that the system

has switched to the air cylinder of the breathing apparatus.

16. Immediately stop venting:

a. Positive-pressure lung demand valve – Press the reset

button on the lung demand valve.

b. b.Negative-pressure lung demand valve – Release the

centre of the rubber cover.

!

!

i

i

!

BA

AL

LDV

3486

1

Dr

äg

er

3487

2

2

3

1

3488

3

2879

4

Reviews: