Graco 312497F Manual De Usuario

Blocks will cause a higher than normal pumping pres-
sure. Depending on the application or system design, 
this blockage will usually result in a complete loss of 
lubricant flow into the total system and no bearing will be 
receiving lubrication.

The loss of flow due to a blockage is first indicated with 
the higher than normal system pressure that is devel-
oped by the pump as it attempts to overcome this block-
age. Higher pressure is limited, isolated and signaled 
through the use of various performance indicators, reset 
and relief, incorporated into the system design.

Performance indicators are pressure-sensitive devices 
that pinpoint excessive pressure in the lubricating sys-
tem.

These devices are installed in the indicator ports of 
divider valves, signal a fault either by causing an indica-
tor pin to protrude or by releasing lubricant into the 
atmosphere. 

NOTE: Never block a lube outlet that is designed to dis-
charge lubricant.

Reset indicators stop lube system operation when a 
fault occurs. These devices can be used in either master 
or secondary divider valves.

When a lube line becomes blocked, the resultant high 
pressure pushes the indicator pin through the opening in 
the cap. The high pressure prevents the affected divider 
valve piston from completing its cycle, causing a pres-
sure backup through the divider valve which trips a pres-
sure switch upstream from the valve and shuts off the 
pump. 

The indicator pin remains extended until it is reset man-
ually. This helps locate the lube line that is blocked.

Rupture indicators are used on MSP/MH divider valve 
applications where lube system pressure exceed 2500 
psi. The high pressure from the lube line blockage 
causes a disc to rupture. The lubricant then forces an 
indicator to protrude, locating the blockage. The high 
pressure backs up through the system and trips a switch 
to shut the system off. When the fault is corrected, the 
disc must be replaced and the pin reset manually.

An automatic relief indicator pinpoints lube line blockage 
but allows the lube system to continue supplying lubri-
cant to points that are not blocked. They are used pri-
marily in secondary divider valves. The excessive 
pressure created by line blockage moves a piston, 
enabling the lubricant to escape through a vent. When 
the pressure is relieved, the spring resets the piston. 
Because these devices permit the lube system to keep 
operating when a lube point is blocked, a separate pres-
sure switch connected to an audible alarm should be 
used to warn of high pressure.

1.

Make a visual inspection of the system. Check for 
crushed lines or improper divider valve installation.

2.

Verify that each divider valve outlet required to dis-
charge lubricant can do so and that no pipe plugs 
have been installed in an outlet designed to serve a 
bearing or another divider valve.

3.

Use a manual pump with a gauge. Fill the pump with 
clean, filtered lubricant. Connect the manual pump 
to the inlet of the master divider valve and slowly 
operate pump. If system will not cycle freely, below 
1500 psi, see Master Divider Valve Equipped with 
Performance Indicator [Step 4a (below)].

NOTE: Use only clean oil filtered to the SAE -recom-
mended cleanliness level of ISO 18/14 (ISO Standard 
4406) when prefilling a system. The manufacturers of 
the machine tool and its component bearings should be 
consulted to ensure that the ISO 18/14 cleanliness level 
is adequate.