TECTULby IMR

Fluid conveyance · Carbon steel check valves

TECHNICAL DATA SHEET

FT-TC-VAL-CHEQUE-AC-001

Issue date: August 4, 2026 · Rev. 001

Check the current version

Carbon steel check valves — Cheque Cortina bolted-cover API 594/BS 1868 class 150, forged Cheque Globo and Cheque Compuerta API 602 class 800

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TECTUL's carbon steel check (non-return) valves in two constructions: the Cheque Cortina, a bolted-cover swing type in A216 WCB per API 594 / BS 1868, class 150 (285 psig at 38 °C); and the Cheque Globo and Cheque Compuerta, forged in A105 per API 602, Class 800 (1,973 psig at 38 °C — not "800 psi"), 1/2″ to 2″, with threaded or socket-weld ends. The closing mechanism — gravity swing, spring-loaded piston or gravity gate — sets the orientation each figure works reliably in: this sheet publishes the type-to-admissible-position matrix that no Spanish-language data sheet details, together with the physics of why a swing check slams on closing.

SKU VT-cheque-cortina-acero-al-carbon-bridado · 3 references: Cheque Cortina flanged class 150 (2″–12″), forged Cheque Globo and Cheque Compuerta class 800 (1/2″–2″)

1. Technical specifications

Three references, two constructions

Regulatory framework

Pressure-temperature table — class 150 (A216 WCB, B16.34 group 1.1)

Pressure-temperature table — Class 800 (A105, group 1.1, interpolated 1/3 class 600 + 2/3 class 900)

Class 150: Table 2-1.1 of ASME B16.34, material group 1.1. Class 800: the 38 °C anchor value (1,973 psig) is verified against API 602 line manufacturers and detailed with the calculation method in the sister gate valve sheet, FT-TC-VAL-COMPUERTA-AC-001, section 2.

Face-to-face dimensions — Cheque Cortina, class 150 (ASME B16.10 swing check pattern)

The face-to-face pattern of the flanged swing check matches the globe valve pattern at the same size in ASME B16.10 (both are "long" bolted-bonnet bodies), and is noticeably longer than a gate valve's (for example 4″: 292 mm versus 229 mm). The forged Cheque Globo and Cheque Compuerta have no F2F table in B16.10; their dimension is set by API 602 and the manufacturer — confirmed on quotation.

2. Check type-to-admissible-mounting-position matrix

The mechanism that returns the closure member to its seat — gravity on a hinge, a spring on a piston, or gravity on a gate — defines the orientation each figure works reliably in. It is the installation datum no Spanish-language commercial sheet publishes as a table.

Classification by mechanism family, applying general check valve installation practice. The admissible position of each figure and the flow direction are defined by the manufacturer: the arrow cast on the body and the product PDF sheet override this table.

Why the forged Cheque Compuerta does not accept downward flow

On the Cheque Compuerta, the force that returns the gate to the seat is its own weight, and that weight only does its job if it acts opposite to the flow: hence the admissible mounting is horizontal — the gate falls onto the seat — or vertical with upward flow — it falls against the stream. With downward flow, gravity and the fluid push in the same direction, the opening one: the gate rests on the open stop and, when flow stops, nothing brings it back to the seat. The valve stays permanently open and the return flow passes freely. This is the most common field error with this family and the network pressure test does not reveal it: it shows up when the pump stops.

Why the spring-loaded Cheque Globo tolerates more orientations

Unlike the two gravity designs, the Cheque Globo's piston closes by the force of a calibrated spring, not its own weight: that lets it work in more orientations, because closing does not depend on gravity acting in the correct direction. The condition remains to verify with the manufacturer whether the spring was calibrated to offset the piston's weight or not in the project's specific orientation.

Field rules common to all three references

• The arrow cast on the body indicates the flow direction, not the mounting position: complying with the arrow does not guarantee correct orientation.
• Leave a straight run upstream, free of elbows, pumps and immediate reducers, so the closure member works with steady flow.
• Size by the service flow rate and not by the pipe diameter: an oversized check valve works with the closure member partly open and wears the seat.
• A check valve is not an isolation valve: to work on the line, an isolation valve is installed upstream.

3. Cracking pressure, metal-to-metal seals and why the swing check slams on closing

Cracking pressure

Cracking pressure is the minimum differential pressure the fluid needs to lift the closure member off the seat and start flowing. On the Cheque Cortina, which opens only by the flow's push against the hinged disc's weight, cracking pressure is low — typically a fraction of a psi in large sizes — enough that the disc's weight is not a meaningful restriction in normal operation. On the spring-loaded Cheque Globo, cracking pressure is set by the spring preload, a value calibrated by the manufacturer (typical orders of magnitude of one to several psi, depending on the application) that guarantees the piston closes even in vertical mounting or against small pressure pulsations, in exchange for additional head loss in normal operation compared with the swing type. The exact cracking-pressure value per reference and size is not published by the manufacturer in the general catalog and is confirmed on quotation.

Metal-to-metal seals

All three references in this sheet seal metal against metal: the disc or gate seats directly on a machined body surface, with no elastomeric or PTFE ring. It is the construction consistent with this family's steam and high-temperature service (where an elastomer would degrade) and with the forged Class 800 (where contact pressure is high). The trade-off against a soft seal is a less perfect shut-off tightness at low differential pressure — metal does not conform to surface imperfections the way an elastomer would — and the need for a seat finish in good condition: scratches or fouling open a leak path that no amount of tightening corrects, because a check valve has no bolt-torque adjustment like a flanged joint.

Why the swing check slams on closing

The Cheque Cortina closes by gravity when flow stops or reverses, and its disc has considerable mass and inertia. If flow stops abruptly — a sudden pump trip, for example — the disc takes a moment to fall and close while the fluid has already begun returning: the disc strikes the seat with the fluid still moving in reverse, and that abrupt deceleration of a moving fluid column is exactly the definition of water hammer (a sudden pressure rise from an abrupt change in fluid velocity). The slam is felt as an audible metallic knock in the valve, and in severe installations (large pumps, long fluid columns, frequent start-stop cycles) it can generate overpressures several times the normal operating pressure, with risk of damage to the valve itself, neighboring flanges or supports.

The spring-loaded Cheque Globo mitigates this effect because the spring closes the piston before the flow fully reverses — before the column reaches a significant return velocity — closing with the fluid nearly at rest instead of moving backward. That is why, on lines with large pumps or frequent sudden stops, a spring-assisted fast-closing check valve reduces water hammer compared with a gravity-only swing type; for severe water hammer, specialized damped anti-slam designs also exist (outside the scope of this sheet), and our technical team should be consulted when the phenomenon is recurring.

4. Frequently asked questions

What mounting position can I use for the Cheque Cortina?

Horizontal — its design position, hinge on the upper horizontal axis — or vertical with upward flow, as confirmed by the manufacturer of each reference. Never vertical with downward flow. The full matrix for all three references is in section 2.

Do the check valves in this sheet really take 800 psi?

The forged Cheque Globo and Cheque Compuerta are ASME B16.34/API 602 Class 800, whose real cold ceiling is 1,973 psig (136 bar) at 38 °C, not 800 psi. The flanged Cheque Cortina is Class 150, 285 psig at 38 °C. See the full correction in section 1.

Why does my swing check valve slam hard when the pump stops?

Because the disc closes by gravity and takes a moment to reach the seat while the fluid has already begun returning: the metallic knock is the disc striking the fluid still moving in reverse, the definition of water hammer. A fast-closing spring check valve (like the Cheque Globo) closes before the return flow gains speed and reduces that slam. The detail is in section 3.

Can I install the Cheque Compuerta with downward flow?

No. The gate closes by its own weight, which only works against the flow. With downward flow, gravity and the fluid push in the same opening direction, and the valve stays permanently open once flow stops — a failure the network pressure test does not detect.

What cracking pressure do these check valves have?

The Cheque Cortina opens with a low cracking pressure, just enough to overcome the disc's weight. The spring-loaded Cheque Globo has a manufacturer-calibrated cracking pressure, on the order of one to several psi depending on the application. The exact value per reference and size is confirmed on quotation.

Do these check valves seal with an elastomer or metal-to-metal?

Metal against metal on all three references, consistent with this family's steam and high-temperature service. Shut-off tightness at low differential pressure is less perfect than with a soft seal, and the seat must be kept free of scratches or fouling.

5. Application notes

6. Technical notice and limitation of liability