Shand & Jurs 97401 U-Tube Manometer

For commissioning engineers, biogas technicians, and combustion specialists, the Shand & Jurs Biogas 97401 U-Tube Manometer provides direct differential liquid-column measurement on inches-water-column systems where small pressure differences determine equipment behavior and fuel efficiency.

Unlike electronic differential transmitters that can drift or fail and hide developing problems, the 97401 compares two pressure points against an indicating fluid column and displays actual pressure drop across filters, flame arresters, and regulators without calibration, electronics, or power.

Optional moisture and sediment traps protect the indicating fluid in wet gas service, and a float check valve prevents fluid displacement during surge events, so the instrument remains ready during commissioning, troubleshooting, and routine verification.

Available in selectable ranges from ±3″ to ±25″ W.C. in English or metric scales with aluminum, steel, or stainless panel options, the 97401 installs as a permanent differential reference on gas trains, burner piping, and digester systems.

Features

Displays true pressure drop between two points independent of transmitter calibration error, revealing restriction, imbalance, or abnormal resistance as it develops in the system.

Single instrument verifies pressure, vacuum, or differential conditions, supporting regulator balance checks and component-resistance measurement during commissioning and troubleshooting.

Optional trap prevents contamination from wet gas that would otherwise require fluid replacement and recalibration, extending service intervals in digester and wet biogas duty.

Float check valve protects the indicating fluid from loss during pressure upset events, preserving instrument readiness and avoiding service calls after process excursions.

Range options from ±3″ to ±25″ W.C. match measurement sensitivity to expected pressure drop, covering regulator balance through flame-arrester fouling detection in one family.

Panel or wall mounting provides a permanent commissioning and troubleshooting reference location, supporting repeatable procedures and straightforward operator verification over time.

Applications

Filter Monitoring: Tracks pressure drop across gas filters, detecting fouling and restriction before flow or combustion performance degrades on burner trains and conditioning skids.
Flame Arresters: Monitors differential across flame arresters in service, identifying element fouling that would otherwise cause pressure drop, flow restriction, and flame-stability problems downstream.
Gas Trains: Verifies regulator balance and component resistance on biogas and fuel-gas trains, supporting commissioning and rebalancing without dependence on electronic differential transmitters.
Burner Piping: Confirms correct pressure drop from burner-train components, supporting stable combustion operation and identifying restriction-related flame instability or nuisance shutdowns.
Digesters: Monitors differential conditions on digester gas-handling equipment in wet methane service, supported by optional moisture traps that prevent indicating fluid contamination.
Utility Gas Lines: Provides a permanent differential reference on utility fuel gas systems, identifying restriction-related changes in performance across shared distribution to multiple consumers.

Specifications

Parameter

Specification

Measurement Types

Pressure, Vacuum, Differential

Range Options

±3″, ±5″, ±7.5″, ±10″, ±12″, ±15″, ±18″, ±25″ W.C.

Scale Options

English (in. W.C.) or Metric

Indicating Fluid

Green, Specific Gravity 1.0

Standard Fluid Temperature

30°F – 100°F

Mounting

Panel or Wall Mounted

Housing Material

Extruded Aluminum

Mounting Panel Material

Aluminum, Steel, or Stainless Steel

Mounting

Panel or Wall Mounted

Float Check Valve

¼” NPT, Stainless Steel with Teflon Float

Vented Petcock

¼” NPT, Brass

Optional Flame Check

¼” NPT for end of vent line

Optional Line Trap

Drain condensation build-up

2026 COST ESTIMATE

Contact Support

If you have questions not covered here, please contact the Cognesense support team for assistance.

When is a differential U-tube manometer required rather than a single-tube manometer?

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When system performance depends on pressure drop across a component — such as a filter, flame arrester, or regulator — rather than on absolute pressure. The U-tube compares two points so pressure drop is visible directly, without relying on separate upstream and downstream readings.

Why measure differential mechanically when transmitters are available?

Mechanical differential measurement is independent of calibration, electronics, and power. Transmitters drift, especially in wet gas, and can hide developing problems. A visible liquid column reveals restriction and imbalance during commissioning and troubleshooting with no instrumentation dependency.

How does the moisture and sediment trap option help?

In wet biogas service, condensation and particulate would otherwise contaminate the indicating fluid, requiring replacement and recalibration. The optional trap captures these contaminants upstream of the manometer, extending service intervals and reducing maintenance labor.

What ranges are available?

Range options span ±3″, ±5″, ±7.5″, ±10″, ±12″, ±15″, ±18″, and ±25″ W.C., so measurement sensitivity can be matched to the expected pressure drop across the specific component being monitored.

Does the float check valve prevent fluid loss during surge events?

Yes. The stainless-steel float check valve with Teflon float prevents indicating fluid from being displaced or blown out during pressure upset events, preserving the instrument’s readiness for inspection after the upset.

How does the 97401 relate to the 97400 well-type manometer?

The 97401 is a U-tube manometer optimized for differential pressure across two points; the 97400 is a single-tube well-type manometer for direct pressure reference. Both provide physical reference measurements independent of electronic instrumentation.

Summary

With over a century of tank-safety heritage inside Cognesense, the Shand & Jurs Biogas 97401 U-Tube Manometer is chosen where system behavior depends on pressure drop rather than absolute pressure. Its differential liquid column, optional moisture and sediment traps, and float-check surge protection deliver direct visual verification of regulator balance and component condition. Installed as a permanent reference on gas trains, filters, and flame arresters, it is trusted wherever you need to measure, monitor, and protect what matters most.

97401 U-Tube Manometer