Connecting Roughing Pump; Connecting Purge Gas Line - Ulvac CRYO-U Series Instruction Manual

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CRYO-U Cryopump Instruction Manual
4.3

Connecting Roughing Pump

１．Connect roughing pump system to the cryopump accessory port or the manifold between
cryopump and main valve. The roughing time can be shorten with a piping which has
bigger diameter.
２．Install a pirani gauge between cryopump and roughing pump. It is recommended to install it
as close as possible to the cryopump.
３．Addition of a fore-line trap in the roughing line is recommended in order to prevent the
cryopump from back stream of oil when rough pumping to 40Pa or less by oil-sealed rotary
pump. Regenerate the fore-line trap if necessary.
4.4

Connecting Purge Gas Line

Connect the gas purge line to the cryopump accessory port referring to Section 1.2, if it is
required for regeneration. Use nitrogen gas that its dew point temperature is -40℃ or below or
argon as the purge gas. Set its flow rate and supply pressure as follows;
(*1)
Flow rate
Supply pressure
(*1)
Larger flow rate may be demanded when pumping flammable gas or oxygen gas into the
cryopump. Please design and construct the flow pathway of the purge gas carefully to ensure
the required flow rate.
In case of using our optional Regeneration Gas Purge PR Unit
type of cryopump), choose an appropriate size and length of the gas purge pipe in order to
maintain the pressure loss in the entire purge gas introduction line to be 5kPaG or less at the set
flow rate. (Refer to Figure 4-4 Pressure Loss of Regeneration Gas Purge PR Unit ΔP
(*2)
Regeneration Gas Purge PR Unit is an all-in-one unit equipped with Purge Gas Introduction
Valve, Purge Gas Exhaust Valve, and Atmospheric Sensor, which makes it easier to connect
gas purge pipe and exhaust pipe. It is also space-saving. The unit comes in three different types
which are PR-1A, PR-2A, or PR-3A. Choose applicable type for your cryopump. Read the
Regeneration Gas Purge PR Unit instruction manual for more details.
(*3)
When regenerating flammable or oxygen gas, the inlet for purge gas and the outlet
from the cryopump should be separated and be set up. In this case, our
Gas Purge PR Unit should not be used. Please design and construct the purge gas inlet and
outlet lines so that dangerous gases can be smoothly exhausted.
: in the range from 20NL/min to 50NL/min
: 10kPaG or less
ULVAC CRYOGENICS INCORPORATED
(*2) (*3)
, (not applicable for a certain
)
pr.
Regeneration
4-5