Exhaust washdown requirements – Labconco Protector Stainless Steel Perchloric Acid Laboratory Fume Hoods 1308 Series Manuel d'utilisation
Page 12
Chapter 2: Prerequisites
Product Service 1-800-522-7658
8
Original instructions
Proper Perchloric Acid blower selection can be determined from these exhaust
requirements and the total system static pressure loss. Contact Labconco
Customer Service for assistance in sizing a blower system.
Exhaust Washdown Requirements
The entire exhaust duct system must feature an adequate washdown system. This
includes the exhaust ductwork, blower, hood structure itself, and any ductwork
located outside the blower. Wash rings are required to be placed in the exhaust
duct system every 8 to 10 feet and after any change in direction to provide
adequate washdown. Contact Labconco for washdown ring ordering information.
Order part number 4746000 for a 10" wash ring and 4746100 for a 12" wash ring.
Depending on the length of duct run and number of wash rings and elevation
differences, Labconco recommends one additional washdown valve for every
three wash rings. The washdown nozzles are designed at a normal pressure of 40
psi with a flowrate of 1 gallon per minute and a minimum pressure of 10 psi with
a flow rate of 0.5 gallons per minute. The washdown nozzle at a maximum
pressure of 100 psi has a flowrate of 1.5 gallons per minute. Each washdown
valve can only produce up to 3.5 gallons per minute at 40 psi and additional
washdown valves are ordered frequently and installed on the fume hood front
corner post. Order 9808310 Washdown Valve Kit (3/8 lines) per sizing chart that
follows.
Airflows and Static Pressure
Eco Energy Saving Air Foil
Hood Type
Face
Velocity (fpm) Airflow Volumetric Rate (CFM) @
Sash at
Sash at 62.5% Static Pressure (inches of water)
Stainless Full open
open
4'
5'
6'
8'
Hoods
at 28"
at 18"
Hood
Hood
Hood
Hood
Perchloric
and
125
200
905, 0.39" 1195, 0.52" 1475, 0.78" 2050, 0.44"
Radioisotope
100
160
725, 0.25"
955, 0.33" 1180, 0.50" 1640, 0.28"
N/A
125
565, 0.15"
745, 0.20"
920, 0.31" 1280, 0.17"
11" OD
N/A
100
455, 0.10"
595, 0.13"
740, 0.20" 1025, 0.11"
Exhaust
Recommendations highlighted