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Series 420 Durablock® Inclined/Vertical Manometer

MARK II 27

Series 250-AF Inclined Manometer Air Filter Gages

Precision Machined, Solid Acrylic Plastic Gages, Accurate To ±1% Of Full Scale

Dwyer® Durablock® Series 250-AF Inclined Manometer Air Filter Gages are precision machined 1" thick solid acrylic plastic, virtually unbreakable and free of distortion. The fluid bore is precision drilled to ±.0002" to assure life-long accuracy. A glass spirit level is built into the body and encapsulated to prevent damage or tampering. The scale is mirror polished chrome plated brass to assure parallax free reading by alignment of the meniscus with its reflection. Safety traps are incorporated in the body to prevent loss of fluid due to pressure surges. Red and green signal flags indicate clearly when a filter change is necessary. Gages are suitable for use in ambient temperatures of -20 to 150°F. Connection fittings are positively sealed but easily removed for zeroing or addition of fluid.

Economy Model 452-AF is similar to the 250 Series except they are not equipped with over pressure traps. Two A-324 1/4" compression fittings are included with each gage but not shown. Bodies are of 5/8" thick acrylic and scales are mirror polished, epoxy coated aluminum. See the Support Library tab for Safety Data Sheets.

California Residents: Click Here for Proposition 65 WARNING.

Product Applications

Air filter gage

Starting at $671.30

Ordering

Grouped product items
Model	Description	Availability*	Price
209-AF	Inclined air filter gage, range .20-0-3.0" w.c., 5-1/2" inclined scale,	1-2 Weeks*	$813.75
250.5-AF	Inclined air filter gage, range .10-0-1.0" w.c., 8" inclined scale,	1-3 days*	$722.85
250-AF	Inclined air filter gage, range .10-0-1.0" w.c., 5-1/2" inclined scale,	1-2 Weeks*	$671.30
251-AF	Inclined air filter gage, range .05-0-.50" w.c., 5-1/2" inclined scale,	1-2 Weeks*	$729.50
252-AF	Inclined air filter gage, range .20-0-2.0" w.c., 8" inclined scale,	1-3 days*	$745.85
350-AF	Inclined air filter gage, range 0-4" w.c., 4-1/2" inclined scale	1-2 Weeks*	$770.60
451-AF	Inclined air filter gage, range 0-1" w.c., 8" inclined scale	1-2 Weeks*	$676.40
452-AF	Inclined air filter gage, range 0-2" w.c., 8" inclined scale, 2 psi max. pressure.	1-2 Weeks*	$700.40

Specifications

For Architects and Engineers
An air filter gage for measuring the resistance to air flow through the filters shall be installed, one for each bank of filters. The gage shall be of inclined tube differential type (equipped with vent valves for zeroing) shall be of solid acrylic plastic construction with built-in level vial (and over pressure safety traps 250 Series only), shall have an adjustable mirror-polished scale, shall be furnished complete with two 5-foot lengths 1/4" tubing, two static pressure tips, mounting hardware, additional bottle of red gage fluid and instructions.

Features

Support Library

Drawings

FAQ

Questions

Question

Is routine maintenance required for a Dwyer red gage fluid type manometer?

Answer

Yes. The zero point should be checked periodically as well as the fluid level. After a year of service, particularly with dirty air, the fluid should be replaced to assure that specific gravity changes are not affecting the accuracy of the reading.

Related

Series 1227

Series Mark II

Series 1230/1235

Series 100

Series 250-AF

Series 420

Series 200 & 300

Series 1221/1222/1223

Series 100 AV

Series 400

Question

We are using a Durablock inclined manometer with a range of 0-0.25" of water. What is considered a normal response time to steady state? We are seeing times of 1 minute whereas the manual states 'a few seconds'. Gage fluid is well beyond the recommended three years. Do I need fresh (i.e. new) gage fluid? My supply is as old as what's in the manometer.

Answer

The manometers have a response time that is dependent on the length of tubing, so a response time of a minute is not uncommon. You may want to check your fittings to make sure there is not a clog present. The gage fluid has a lifespan of three years before the inherent properties start to change, so it is suggested to replace it. A one ounce bottle of fluid is p/n A-101.

Related

Series 250-AF

Gage Fluids

Reviews

Accessories

Model	Description	Availability*	Price
A-101	1 oz dispenser bottle of red gage fluid, .826 sp. gr.	1-3 days*	$11.75
A-102	4 oz bottle of red gage fluid, .826 sp. gr.	1-3 days*	$22.70
A-103	1 pt bottle of red gage fluid, .826 sp. gr.	1-3 days*	$50.05
A-104	1 qt bottle of red gage fluid, .826 sp. gr.	1-3 days*	$94.20
A-210	Aluminum tubing is recommended for permanent installations. 1/4" OD, 5' length, 500 psi maximum pressure @ 200°F.	17-18 Weeks*	$8.70
A-310B	3-way vent valve, plastic, 1/8" NPT to 1/4" metal tubing, 10 psi rating.	1-3 days*	$16.75
A-317	Gage connector, 1/8" pipe thread opening, less OD thd., for slip fit in 3/4" dia opening in 250 Series AF gages.	1-2 Weeks*	$26.00
A-322	Gage connector for 1/4" tubing, slip fits in 3/4" opening in 250 Series AF gages (compression nut and ferrule not included).	1-3 days*	$11.00
A-324	Compression fitting, brass 1/8" NPT to 1/4" metal tubing.	Call for Details*	$5.90
A-603	"T" kit, accessory package for using pressure switch in conjunction with an air filter kit equipped Magnehelic® or Series 250 AF gages, includes two 1/8" NPT to 1/4" tubing compression fittings & two compression tees.	Less Than 1 Week*	$26.75
420103-00	Red scale arrow.	1-2 Weeks*	$3.30
420104-00	Green scale arrow.	1-2 Weeks*	$3.30