VICI NPM - Manual (Page 4)

2
Gases purified
Max. operating pressure
Max. operating temperature
Max. flow rate
Impurities removed
Impurities not removed
He, Ne, Ar, Kr, Xe, Rn
200 psig
400°C
30 cc/min
Outlet impurities less than 10 ppb
H
2
O, H
2
, O
2
, N
2
, NO, NH
3
, CO, and
CO
2
, based on 100 ppm total inlet
impurities. Other impurities
removed include CF
4
, CCl
4
, SiH
4
,
and hydrocarbons such as CH
4
He, Ne, Ar, Kr, Xe, and Rn
He, Ne, Ar, Kr, Xe, Rn, N
2
200 psig
400°C
30 cc/min
Outlet impurities less than 10 ppb
H
2
O, H
2
, O
2
, NO, NH
3
, CO, and
CO
2
, based on 100 ppm total inlet
impurities. Other impurities
removed include CF
4
, CCl
4
, SiH
4
,
and hydrocarbons
He, Ne, Ar, Kr, Xe, Rn, CH
4
, and N
2
Helium Purifier
(HPM)
Nitrogen Purifier
(NPM)
Introduction
Specifications
Theory of Operation
The purification substrate in the Valco purifiers is a non-evaporable
gettering alloy. The alloy must be heated so that the oxide layers
on the particle surface are eliminated. This process must be
performed under a vacuum or in at atmosphere of helium (for the
HPM) or nitrogen (for the NPM).
Although the gettering alloy will purify even at ambient temperatures,
raising the temperature vastly improves the life span and efficiency
of the alloy. However, the elevated temperature causes hydrogen
generation, which is trapped only at temperatures below 250°C.
Accurate temperatures are maintained with the use of the precision
24 VDC power supply which is supplied with the HPM/NPM.
Power Supply Requirements
As stated on the purifier, the power supply must conform to
EN 61010-1: Section F.2.1 Limited circuit. This section mandates
that the power source must be limited to 42.4 VDC or less (open circuit).
In addition, the energy must be limited by one of the following means:
• the current under any condition of load, including short circuit,
is not more than 8A measured after 1 minute of operation
• the source is rated
or set to limit its power to 150 VA under any con-
dition of load
• an overload protector or circuit component opens to interrupt the
power output at a lower value than 150 VA under any condition
including short circuit