SEMI F22-0697 GUIDE FOR GAS DISTRIBUTION SYSTEMS.pdf

SEMI F22-0697
GUIDE FOR GAS DISTRIBUTION SYSTEMS
1 Purpose
5.2 Terminology
This reference document is intended to outline for the 5.2.1 air-operaled valves(do1)Are those which
user the common systems configurations, components, require pneumatic energy to initiate or terminate flow
and subcomponents of high purity gas distribution sys- or to change flow path(e,g,, normally closed, partiall
tems in a semiconductor fabrication facility. Related open, double acting)
specifications are also noted
5.2.2 aulomatic shutoff valve(ASO)-a mechani
cally, electrically, or pneumatically activated valve
2 Scope
hich has the sole purpose of terminating flow if a
2.1 Outlined in this document are both bulk and spe- predetermined condition is exceeded For cryogenic
cialty gas distribution systems
supply systems, ASOS are used in conjunction with a
2. 2 Components and subcomponents are identified low temperature sensing device
from the point-of-supply to the point-of-connection to 5.2.3 check valve A mechanical gas system compo
the process tool
nent which prevents reverse flow
3 Limitations
2.4 ef/luen lrealment system-a device which
through mechanical, chemical, cryogenic, absorbent,
3. 1 The gas distribution system configurations noted
or other means, abates hazardous gas effluent to"envi
in this reference document are provided solely as a
ronmentally safe levels "through dilution, neutraliza
guide to indicate common industry practice
tion, entrapment, or distillation
not presented as, or intended to be, a representation of
best engineering practice.
5.2.5 excess /ow device-a mechanical or electrica
component which senses and signals an AOV or itself
3. 2 The reference documents noted are provided for to terminate flow in the event predetermined flow s
general guidance only and are not intended to portray
exceeded
code compliance protocol. The users should always
consult local authorities to determine specific applica- 5.2.6 face seal fitting-a high purity fitting which
ble codes and regulations. Agencies, regulatory or oth- Io
incorporates two machined faces and a metallic gasket
erwise, noted herein are representative only of the U. S
within a male/female nut configuration to attain a high
leak integrity seal
3. 3 Specifcations SEMI Standards or other are noted
to assist the user as a reference only
5.2.7flr
boron
device, generally constructed
of polymer, metal, or ceramics and housed in a metal
4 Referenced Documents
chamber, which traps particles, preventing them from
being transported downstream
None
5.2.8/ low restriclor-a component, generally an ori
5 Terminology
fice, which prohibits gas flow beyond a predetermined
5.1 Acronyms
flow
5.1.1 AOV Air-operated valves
5.2. 9 gas box-a gas distribution subsystem which
generally contains the final shut-off valve(S)prior to
5.12 ASO Automatic shutoff valve
the POC. It may also contain filter(s )and a regulator
5.13 Poc-point of connection
5. 2.10 hazardous gas detectors Analytical instru
5.14 POU Point ofus
ments which placed in strategic locations in ane
around gas distribution systems and components are
51.5 Wmb-valve manifold box
used to detect potentially unno