ATR stainless steel check valves use metal-to-metal seating for demanding high-temperature, low-temperature and compatible solvent applications. G (BSPP) female thread and weld-end models are available. Select the standard or HT configuration, body material and model-specific pressure rating together; allowable working pressure reduces as temperature rises. 316L configurations require confirmation for bulk special orders.

ATR Metal-Seated Check Valve Selection

The ATR is a stainless steel check valve with metal-to-metal seating for high-temperature, low-temperature and compatible solvent applications where elastomer seals are unsuitable. This hard-seat design is available with G (BSPP) female threads or weld ends. Choose the complete configuration for the actual medium, pressure and temperature.

Standard and HT Versions: Check the Material Limit

The catalogue identifies a standard version, with no HT code, for -196°C to +300°C and an HT version for higher-temperature service. The HT designation alone does not mean that every body material is suitable for +600°C.

• 304 stainless steel: standard body material. The pressure-temperature table provides factors up to +500°C and no values at +550°C or +600°C.
• 316L stainless steel: listed as a bulk special-order body option. The table includes factors up to +600°C; confirm the HT configuration, availability and permitted pressure for the ordered model.
• Low-temperature service: the catalogue range extends down to -196°C. Confirm the complete assembly, medium, pressure and any application-specific testing or documentation requirements.

Working Pressure Must Be Derated with Temperature

The maximum series rating is 400 bar, but the rating varies with model and connection. For example, the threaded table lists ATR-G1/4-SS at 400 bar, ATR-G1/2-SS at 315 bar and ATR-G11/4-SS at 250 bar. The weld-end table lists K-ATR-12L-SS at 315 bar and K-ATR-22L-SS at 250 bar.

Allowable working pressure = the selected model's maximum working pressure × the applicable temperature factor. Use the pressure-temperature table only within the limits of the confirmed version and material. The highest temperature and highest pressure shown for the range are not a combined operating rating.

Temperature derating describes the permitted operating pressure. It is separate from the pressure drop caused by flow through the valve.

Confirm the Connection and Cracking Pressure

The listed threaded ATR models use G (BSPP) female connections from G¼ to G1¼. The weld-end models cover tube outside diameters from 12 to 35 mm. Match the model to the mating connection, tube dimensions and installation drawing.

The standard ATR cracking pressure is 0.4 bar, with the catalogue specifying a deviation of ≤ ±30%. Cracking pressure is the differential pressure at which opening starts; it does not specify the valve's maximum working pressure or its flow capacity. Read the guide to check valve cracking pressure vs working pressure for the distinction between these terms. Use the ATR data on this page for ATR selection.

Prepare an ATR Selection Enquiry

Provide the medium and concentration, minimum and maximum temperatures, operating and transient pressures, flow rate, allowable pressure drop, connection and size, required cracking pressure, and leakage acceptance criteria. Include the quantity and any material certificates or testing documents required for your project.

Request ATR model and configuration support, or use the stainless steel check valve selection checklist to organise your operating requirements. Confirm the exact model and applicable pressure-temperature limits before ordering.

Frequently Asked Questions

Can an ATR check valve operate at 400 bar and +600°C?

Do not combine those two range limits. Select the model, body material and standard or HT version first, then apply the temperature factor. The model-specific pressure limit and the material's temperature limit both apply.

Does a metal seat mean zero leakage?

Metal-to-metal seating describes the sealing construction, not a zero-leakage guarantee. Specify the medium, test conditions and permitted leakage, and confirm the acceptance criteria for the ordered valve.

Is every ATR valve available in 316L?

304 is the standard body material in the ordering information. 316L is listed as a bulk special-order option; confirm the exact configuration, quantity and availability with Eagle Fluid.

How do I select an ATR for a cryogenic application?

Start with the catalogue's minimum-temperature reference and verify the complete configuration for your medium and operating conditions. A listed temperature range does not by itself establish oxygen-service suitability, a cryogenic test approval or project-specific certification.

Pressure-Temperature Table, Drawings and Model Dimensions

Use the following tables and drawings to check the selected model, connection, dimensions and temperature derating. Dimensions are in millimetres unless otherwise stated.

Check Valve working pressure-Temperature Table

Allowable Working Pressure Reduces as Temperature Rises

1) Female Threaded Check Valve

Ordering Information

Table of Technical Data [mm]

2) Welded Check Valve

!! WARNING: Apply stainless steel-specific lubricant PASTE to the contact surface between the welded pipe nipple and the valve, as well as the internal thread of the lock nut (see the product page for ferrule‑preinstalled fittings and lubricants).

Ordering Information

Table of Technical Data [mm]