METALJET D2+
Revision 19, November 2016
Page 6-2
6.1
Vacuum system
6.1.1
Roughing pump
Background:
Over time, the diaphragms inside the pump wear out and cause the base pressure of the pump to
increase. This eventually limits the turbopump performance resulting in poor vacuum levels. Pump service
involves replacing the diaphragms and occasionally replacing bearings. Excillum offer rouging pump service
through a replacement program.
Excillum recommendation:
Roughing pump performance is monitored by a vacuum sensor which detects and
signal through software when pump performance becomes inadequate.
We therefore suggest that service is driven by pump performance unless preemptive maintenance is required
by customer.
Manufacturer information:
Manufacturer gives no information on preemptive service interval but claim
normal lifetimes in excess of 10000 hours for diaphragms and valves. Bearings have a typical durability of
40000h. Motor capacitors have a typical durability in the range of 10000 to 40000h depending strongly on
operating conditions including ambient temperature, humidity and load.
Service instructions:
Service manual under Section
Replace roughing pump
.
6.1.2
Turbopump
Background:
The bearing of the turbopump rotor is lubricated by a filtered circulating fluid reservoir. Both the
bearing itself and the fluid reservoir eventually need to be replaced in order for the pump to function properly.
Excillum offer turbopump service through a replacement program.
Excillum recommendation:
Turbopump performance is monitored internally by the pump to shut it down in
case current draw or temperature thresholds are exceeded.
We therefore suggest that service is driven by when the turbopump repeatedly shuts down due to high
temperature or high current draw, when troubleshooting efforts have ruled out other sources of failure, such
as insufficient cooling water or vacuum leaks. Preemptive maintenance should be performed if required by
customer.
Manufacturer information:
Manufacturer recommends changing the operating fluid reservoir at least every 4
years and to change the turbopump bearing at least every 4 years.
Service instructions:
Service manual under Section
Replace turbopump
.
6.2
Jet system
6.2.1
Jet pump lubricants
Background:
The jet pump uses two types of oil to lubricate moving parts. Over time, wear debris from the
moving parts inside the pump are accumulated and the lubricants eventually need to be replaced.
Excillum recommendation:
Excillum have extended experience with letting these pumps run without replacing
the lubricants for several years without performance degradation or oil leakage. However, wear debris in the
lubricants can create damage to the internals which then leads to a shorter lifetime of the pump.
We therefore recommend scheduling a drive unit and hydraulic oil replacement at least every two years or
when replacing the pump diaphragm unless preemptive maintenance is required by customer. This should
typically be performed when other service is required.