Series-160

Supported Applications

The Dwyer Series 160 Stainless Steel Pitot Tube is designed for measuring air velocity in ducts. The instrument connects differentially to a manometer to measure velocity pressure, which is then converted to air velocity. An included Air Velocity Calculator computes velocity based on air density corrected for conditions of temperature and pressure.

Operating Conditions & Performance

The series measures air velocity in the range of 0.01 to 2 inches of water (velocity pressure), corresponding to 400 to 20,000 FPM (feet per minute). Accuracy is specified as ±2% for laboratory applications and ±5% for field tests when center velocity is multiplied by 0.9.

Performance depends on installation geometry: duct diameter must be 30 times the pitot tube diameter or greater to achieve ±2% accuracy. The instrument requires smooth, straight duct sections with a minimum of 8½ diameters upstream and 1½ diameters downstream from the pitot tube; an egg crate type straightener is recommended upstream.

The velocity indicated by standard readings applies to dry air at 70°F, 29.9" Barometric Pressure, and a resulting density of .075#/cu. ft. For air temperatures other than 70°F, correction curves provided in the documentation must be referenced. The 5/16" models are rated for process temperatures up to 1500°F (815.5°C).

Configuration Options

The Series 160 is constructed from No. 304 stainless steel with permanently etched inch graduations showing depth of insertion for traversing. The static pressure port is parallel to the sensing tube to allow quick, easy alignment with air flow.

Model Families and Dimensions

• Standard Models (5/16" diameter): Insertion lengths range from 8-5/8" to 60-5/8". Longer models up to 96" are available with a stiffener.
• Pocket Size Models: Series 166 and 167 feature a 1/8" diameter with insertion lengths of 6" or 12".

Mounting Options

The series supports hand mounting or fixed mounting configurations. Available accessories include:

• A-159 Mounting Gland: A two-part stainless steel fitting for permanent, secure mounting on Series 160 tubes made after Dec. 1990. It includes a graphite bushing to assure a leak-proof seal at higher temperatures; TFE bushings are also available.
• A-158 Split Flange Mounting: Zinc plated steel with a 1/16" Neoprene gasket for a leak-proof seal against the duct. Includes nuts and washers.
• A-156 Flange Mounting Plate: Features a 1/2" female NPT connection, used in conjunction with the A-159 gland for flange mounting applications.

Additional Accessories

• Air Velocity Calculator: Furnished with each pitot tube to eliminate tedious calculations.
• A-160-CASE: Carrying case for tubes up to 48" long.
• A-397 Step Drill: Drills six sizes from 3/16" to 1/2" in sheet metal ducts with automatic de-burring.

Key Product Differences

The series is offered as a universal model that fits user-supplied 3/4" schedule 40 pipe. Model numbers follow the pattern 160-<Insertion Length Code> for standard tubes and 166/or 167-<Insertion Length Code> for pocket size models (e.g., 160-8, 166-6). The -CF suffix denotes a 1/8" male NPT compression fitting mounting option available for Series 166 and 167.

The design meets ASME 'Fluid Meters' 6th Ed., ANSI/AMCA 210-99, ANSI/ASHRAE 51-1999, and British Standard 1042 specifications. A kit (Model 160-KIT) is available containing models 160-18, 160-24, 160-36, 160-48, and a carrying case.