Dover Blackmer DMX IV 매뉴얼 - 페이지 7

{카테고리_이름} Dover Blackmer DMX IV에 대한 매뉴얼을 온라인으로 검색하거나 PDF를 다운로드하세요. Dover Blackmer DMX IV 15 페이지. Air elimination system

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4. SYSTEM CONSIDERATIONS (continued)

• The low Flow Detection Flowrate is the lowest flowrate

before the Flow detector activates high pressure.

• The final low pressure setting on the ACP must be at

least 10 PSI (0,68 bar) higher than the setting cor-

responding to the Flow Detection Flowrate. This

margin will compensate from line losses variations in

the system during normal operation, that could other-

wise prevent the system from going to high flow.

FAILURE TO HAVE A SUFFICIENT MARGIN BETWEEN THE

FLOW WANTED AT LOW ENGINE SPEED/IDLE AND THE FLOW

DETECTION FLOWRATE WILL LEAD TO UNSTABLE HIGH FLOW

OPERATION, DEPENDING ON LINE LOSSES AND VARIATIONS

OF THE SYSTEM.

If the flowrate is not acceptable, refer to the appropriate

IOM for the Flow Detector setting procedure.

If the low flow regulator of the ACP does not allow an

increase of 10 PSI (0,34 bar) from the pressure setting

the Flow detector, reduce the Flow Detector setting as

described in the Flow Detector IOM.

After setting the regulator pressure, push down on the

air regulator adjusting knob to lock it in position.

The line going from the Flow Detector to the ACP has

restricted flow.

AIR LEAKAGE FROM THE FLOW DETECTOR TO THE AIR

CONTROL PANEL WILL NOT BE COMPENSATED BY EXTRA

FLOW COMING FROM FLOW DETECTOR AND WILL CREATE

SYSTEM FAILURE : "NO HIGH FLOW".

No accessories or T-connections are allowed between

the Air Control Panel and the outlet of the Flow Detector.

4.6 AIR SEPARATION - STOPPING FLOW

WHEN AIR ENTERS DMX

When no liquid is present or air is detected in the DMX,

the main float will go down, which will release the pres-

sure on the TXD pump air/relief valve. The pump dis-

charge pressure will be less than the pressure required

to open the flow detector check valve. Flow will stop.

Refer to DMX and Flow detector IOM to meet the instal-

lation requirements of the DMX components.

4.7 AIR SEPARATION - AIR FREE METERED

DELIVERY

To perform its air elimination function properly and prevent

air being pumped through the meter, the DMX requires a

minimum discharge pressure downstream of the pump to

be above a given minimum once the system is primed.

Performance tests have demonstrated that the following

pressure settings are typical for operation with DMX and

TXD pumps :

Pump back pressure required for

proper air elimination (TXD2 & 2.5)

Pump back pressure required for

proper air elimination (TXD3)

NT 201B-A00 04.06 DMX IV Air elimination system e

NOTICE :

10 PSI (0.7 bar)

32 PSI (2.2 bar)

IT IS THE INSTALLER'S RESPONSIBILITY ON EACH TRUCK TO

CHECK THAT THE PUMP BACKPRESSURE IS SUFFICIENT TO

ALLOW THE DMX TO PERFORM ITS AIR ELIMINATION FUNC-

TION PROPERLY. ADDING MORE BACKPRESSURE WILL

RESULT IN UNACCEPTABLE PERFORMANCE DURING

WEIGHTS AND MEASURES SPLIT COMPARTMENT TESTING.

The Blackmer Flow Detector acts as a proper pressure

and check valve for TXD2 and TXD2,5 pumps. See the

DMX system and Flow detector IOM for details.

An additional pressure valve with a minimum setting of

22 PSI (1.5 bar) must be used between the meter and

the Flow Detector when the DMX is used in combination

with TXD3 pumps.

The pressure valve setting may be obtained by using

several pressure valves, with a cumulative pressure

above the required setting for the pump used in conjunc-

tion with the DMX.

To evacuate the air trapped between the DMX and the

meter, a Scavenging Line is required. See DMX IOM for

rules on how to install a scavenging line.

The scavenging line must be connected to the piping at

the highest point directly before the meter. The piping

MUST be horizontal.

The piping between the DMX and the scavenging line

must not have a point higher than the scavenging line

connection.

FAILURE TO MEET SCAVENGING LINE INSTALLATION CRITERIA

WILL LEAD TO AIR ELIMINATION SYSTEM FAILURE (A DIFFE-

RENCE BETWEEN PROVER AND METER READING IN SPLIT

TEST CONDITIONS).

4.8 OPERATION AGAINST A CLOSED DISCHARGE

VALVE

The pump internal relief valve protects the pump when the

nozzle is closed and the truck is running. The high pres-

sure regulator of the ACP must be set below the maxi-

mum acceptable pneumatic pressure of the pump

air/relief valve. See the TX Air/Relief Valve IOM for details.

4.9 LIQUID HANDLING FROM DMX TO FLOW

DETECTOR

Follow piping and installation requirements described in

the appropriate IOM.

7/15

NOTICE :