Sample Intake Screen Specification
: The intake screen shall be of all-welded,
continuous slot profile wire construction to provide the maximum open
area commensurate with the strength requirements as per section 3
below. The inlet slots shall widen inwardly from the screen surface so
as to minimize the entrapment of debris in the screen openings. The
design shall include low head loss flow field control.
: The screen assembly capacity shall be 999 litres per second at
a maximum approach velocity of 0.114 metres per second for
subcarangiform fish protection or 0.038 metres per second for
anguilliform fish protection. At this flow rate the pressure drop
through the clean screen surface shall not exceed 0.7 kilopascals (0.1
psi). Pressure drop through the screen assembly shall be in the range
of 0.75 kilopascals (0.11 psi) at rated flow.
: The screen shall withstand a differential hydrostatic collapse
pressure in excess of 30 kilopascals. Maximum allowable design stress
when determining strength shall be 1476 kilograms per square
centimetre. Strength calculations verifying compliance with these
criteria shall be provided upon request.
: The surface wire shall be profile wire of 1.8mm head width with
a 5°-10° relief angle for slots less than 635mm and profile wire of
head width with an 5°-10° relief angle for slots of 6.35mm and larger.
surface wire, support rod, and stiffener structure shall be of
all-welded construction designed to provide the specified strength with
minimal interference with the through-screen flow pattern. All
structural butt welds shall be full penetration; structural fillet weld
size shall be the thickness of the thinner component. An internal flow
field modulator shall distribute flow evenly across the entire screen
: The screen slot size shall be 2.54 mm. The open area for this
slot opening shall be 58.5%. Slot size shall be controlled and
continuously monitored during manufacture. No slot opening in the
assembly shall exceed the designed slot opening by more than 0.15mm.
: The screen assembly shall be manufactured of type 304 stainless
steel throughout. The outlet flange shall mate with a 999 NB flange
with a flange bolt pattern equal to ANSI Class 150.