Domestic natural gas hose — NTC 3561
TECTUL · Dispatch across Colombia · Exports to Central & South America
Hose for conveying natural gas to domestic stoves, ovens and heaters, without direct flame exposure. Carries the NTC 3561 quality seal, which the manufacturer declares it exceeds. Available in 5/16″ and 3/8″ (3/8″ is the most used diameter), with a 17.5 bar working pressure at both diameters. Includes the coupled variant (with a pre-installed 3/8″ fitting) for direct installation on appliances.
Important: Before using these data in engineering, design or installation decisions on systems exposed to mechanical, pressure, rupture, fatigue, impact or water-hammer risk, it is essential to read the technical notice and limitation of liability at the end of this sheet.
VT-86958 · Flexco natural gas hose, NTC 3561
1. TECHNICAL SPECIFICATIONS
| Internal diameter in | Internal diameter mm | OD mm | W/P bar |
|---|---|---|---|
| 5/16″ | 8.0 | 13.4 | 17.5 |
| 3/8″ | 9.5 | 15.6 | 17.5 |
| Parameter | Value |
|---|---|
| Quality seal | NTC 3561 (manufacturer declares it exceeds it) |
| Declared use | Natural gas to stoves, ovens and heaters, without direct flame exposure |
| Most used diameter | 3/8″ |
2. Why "without direct flame exposure" is a real restriction
The manufacturer explicitly restricts use to equipment where the hose is not directly exposed to fire (domestic stoves, ovens and heaters under normal installation). This is a flexible connection hose, not a rigid supply line: its function is to join the service valve or regulator to the appliance, a short and visible run, not an embedded or buried installation. NTC 3561 is the Colombian technical standard for flexible fuel gas hoses for domestic, commercial and light industrial use; the manufacturer declares it exceeds this standard, but the specific lot's quality-seal certificate is confirmed on quotation.
Coupled variant
The variant with a pre-installed 3/8″ fitting (manguera-gas-natural-flexco-acopladas) is the same hose construction with the coupling already factory-mounted, for direct installation without on-site crimping.
3. FREQUENTLY ASKED QUESTIONS
Can it be installed near the burner flame?
No: the manufacturer restricts use to installations without direct flame exposure, typical of the connection between the valve/regulator and the appliance.
What is the difference with the coupled variant?
None in the hose itself: the coupled variant comes with the 3/8″ fitting pre-installed at the factory, ready to install without additional crimping.
What standard certifies this hose?
NTC 3561, the Colombian technical standard for flexible fuel gas hoses; the manufacturer declares it exceeds it.
4. Application notes
Feasibility
Confirm the specific lot's NTC 3561 certificate with the supplier before installing in a regulated service.
Installation
Do not install where directly exposed to the burner flame; use only as a connection between the valve/regulator and the appliance.
Design
Verify the appliance's connection diameter (5/16″ or 3/8″) before quoting the coupled variant.
5. Technical notice and limitation of liability
The pressures, dimensions, weights and other characteristics in this sheet are theoretical calculation values obtained from nominal properties published in the standards cited (ASME B36.10-2022, ASME B31.3-2024, ASTM A106/A106M-19a, ASTM A53/A53M-24, API Spec 5L 46th ed.). They guide selection; they are not a certificate of conformity for any given lot.
The actual behavior of each lot varies with manufacturing — wall tolerance (up to −12.5%), out-of-roundness, residual stresses — and with the raw material — chemical composition within the ranges the standard allows, heat-to-heat differences. To certify a lot, the tests defined by its product standard are required: tensile test, flattening test and hydrostatic test, documented in the manufacturer's mill test certificate (MTC), which TECTUL supplies upon request; testing of the lot in an independent laboratory can also be arranged.
These values must not be used as the sole criterion in critical or safety applications, or wherever failure of the line may compromise people, property or the environment: in such cases the design belongs to the project's responsible engineer under the applicable code (ASME B31.3, B31.1 or the one governing the installation), with the design temperature, corrosion allowance and load cases of the actual service. Before deciding with these data, consult our technical team.
Sources
- NTC 3561 (mangueras flexibles para gas combustible)
- Ficha de fabricante «Manguera Gas Natural Flexco» (archivo interno)
This data sheet is the property of TECTUL, part of the Industrias IMR group. Reproduction without attribution is prohibited. Original document and updates: tectul.com/en/conduccion-de-fluidos/mangueras/ficha-tecnica-manguera-gas-natural-flexco.