Shand & Jurs 97220 Back Pressure Check Valve

For biogas engineers, treatment-skid designers, and low-pressure fuel-gas specialists, the Shand & Jurs Biogas 97220 Back Pressure Check Valve prevents reverse flow and downstream pressure migration in low-pressure gas systems where staged pressure zones must be preserved.

Unlike spring-loaded check valves that can chatter or leak in low-differential service, the 97220 uses a gravity-assisted sealing element that remains seated under normal conditions and lifts only when forward differential pressure exceeds the gravity closing force.

When downstream pressure rises or flow reverses, the element reseats immediately to isolate upstream piping and prevent pressure stacking, backfeeding of air, and contamination of upstream regulators or conditioning equipment.

Rated for 5 psig maximum working pressure in aluminum or 316 stainless construction with flanged connections, the 97220 installs downstream of regulators, burners, compressors, and conditioning stages in digester and landfill gas service.

Features

Gravity-assisted pallet provides automatic non-return protection without springs or external actuation, avoiding chatter and leakage common in low-differential check valves.

Opens with minimal forward pressure to avoid unnecessary system restriction, preserving upstream regulator headroom and keeping gas-train pressure drop as low as possible.

Element reseats immediately when downstream pressure exceeds upstream pressure, isolating upstream piping from backflow and preventing pressure stacking during system upsets.

Full-port flow passage maintains gas capacity without significant pressure drop, so the check valve drops into existing headers without resizing or flow rebalance.

Designed for stable horizontal operation in low-pressure gas piping, delivering consistent gravity-assisted closure across the operating range typical of biogas headers.

Flanged body integrates directly into standard low-pressure piping runs, supporting inspection and service without custom fittings or adapter spools during installation.

Applications

Biogas Piping: Installed downstream of regulators and conditioning equipment to preserve directional flow and keep staged pressure zones stable across the biogas distribution system.
Digester Gas Trains: Protects digester gas conditioning sequences from backflow, keeping upstream treatment stages isolated from downstream pressure variation during flare or burner events.
Flare Headers: Installed on flare header branches to prevent reverse flow into upstream gas sources, stabilizing flare supply pressure and protecting upstream conditioning equipment.
Gas Conditioning Skids: Maintains pressure zones between filtration, separation, and regulation stages on biogas conditioning skids, preventing cross-contamination and upstream pressure stacking.
Low-Pressure Fuel Gas: Installed on low-pressure fuel gas headers feeding burners and boilers, preventing reverse flow during downstream pressure events and keeping supply zones isolated.
Compressor Discharge: Installed downstream of blowers or compressors, preventing reverse pressure loading of the discharge line during shutdown or trip events on gas-handling skids.

Specifications

Parameter

Specification

Service

Low-pressure gas systems

Operation

Automatic non-return (gravity-closing)

Mounting

Horizontal

Connection

Flanged

Body, Pallet, Pallet Arm, Seat Ring

Aluminum (standard); 316 Stainless Steel (optional)

Soft Goods

NBR

Hardware

Stainless Steel

Working Pressure

5 psig maximum

2026 COST ESTIMATE

Contact Support

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

Why use a gravity check valve instead of a spring-loaded design?

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At the low differentials typical of biogas service, spring-loaded checks can chatter or leak. The 97220’s gravity-assisted pallet remains seated under normal conditions and lifts only when forward flow exceeds closing force, giving reliable non-return behavior in low-pressure service.

Where in the gas train should the 97220 be installed?

Install downstream of regulators, burners, compressors, or conditioning equipment where directional flow must be preserved. The check valve isolates upstream piping from downstream pressure fluctuations and prevents backfeeding of air or contaminated gas.

What pressure and materials are available?

The 97220 is rated for 5 psig maximum working pressure. Body, pallet, pallet arm, and seat ring are aluminum standard or 316 stainless optional; soft goods are NBR; hardware is stainless steel. Connections are flanged for direct pipe integration.

Does the 97220 provide positive shutoff isolation?

No. The 97220 provides automatic non-return protection but is not a positive-shutoff isolation valve. For applications requiring positive shutoff, use manual or actuated isolation valves in addition to the check.

What mounting orientation is required?

Horizontal mounting is required for proper gravity-assisted closure. Installing outside the specified orientation changes the closing force and can affect sealing reliability in low-differential service.

Does the check valve require utilities or controls?

No. The 97220 is fully passive; gravity and differential pressure operate the pallet. No air, electrical, or control signal is required, which makes it a dependable safeguard within low-pressure biogas trains without added utility infrastructure.

Summary

With over a century of tank-safety heritage inside Cognesense, the Shand & Jurs Biogas 97220 Back Pressure Check Valve is chosen where low-pressure gas systems must hold staged pressure zones and block reverse flow. Its gravity-closing pallet, low cracking differential, and full-port geometry protect upstream regulators and conditioning equipment without springs or utilities. Installed in biogas piping, digester gas trains, and gas-conditioning skids, it is trusted wherever you need to measure, monitor, and protect what matters most.

97220 Back Pressure Check Valve