TECTULby IMR

Pipe sealing and joining · PTFE thread seal tape

TECHNICAL DATA SHEET

FT-TC-SEL-CINTA-001

Issue date: August 4, 2026 · Rev. 001

Check the current version

PTFE thread seal tape — standard density and full density for gas

TECTUL · Dispatch across Colombia · Exports to Central & South America

100% virgin PTFE thread seal tape: white, standard-density (SKU VT-58705, 1/2″–1″) for water, air and oil, and yellow, full-density for natural gas or LPG (SKU VT-58703, 3/4″), required by Colombia's gas code NTC 2505 under BS 7786 or MIL-T-27730-A. Density — not color — is what certifies the yellow tape for gas.

SKU VT-58705 (white industrial tape, 1/2″–3/4″–1″) and SKU VT-58703 (yellow gas tape, 3/4″ in two roll lengths) · sold by the unit

1. Technical specifications

Two products, one polymer, different density

TECTUL sells two references of 100% virgin, unsintered polytetrafluoroethylene (PTFE) thread seal tape: the white industrial tape (SKU VT-58705), standard density, for water, compressed air, oil and compatible general services; and the yellow gas tape (SKU VT-58703), full density, color-coded for natural gas or LPG installations. What certifies gas use is the density of the compacted PTFE in the tape, not the color: yellow is only the visual signal of that density.

TECTUL catalog presentations

The Cellux factory catalog for the yellow line publishes two roll lengths at the same 3/4″ width: code C-TG-001808 (8 m, box of 500 units) and code C-TG-001815 (15 m, box of 250 units). TECTUL's product page does not state the roll length of each SKU (VT-58703-01 and VT-58703-02): mapping each SKU to its factory roll length is confirmed on quotation.

General specifications

2. Standard density vs. full density: the real difference between white and yellow tape

What "full density" means in a PTFE tape

The unsintered PTFE in a seal tape is not a homogeneous material: it is manufactured by compressing the resin, and the degree of compression sets its density. Lower density makes the tape more porous, softer and bulkier per gram; higher density makes it more compact, more resistant to gas permeation through its own structure, and better at filling the clearance of a tapered NPT thread. The industry commercially classifies these densities in several tiers — standard, medium, high and full — with no single universal number: each manufacturer sets the cutoff of each tier at somewhat different values.

The one figure that is standardized: 1.2 g/cm³ minimum

US federal specification A-A-58092 (January 7, 1997, superseding MIL-T-27730A ASG), originally written for PTFE tape in liquid and gaseous oxygen systems, requires a minimum density of 1.2 g/cm³ and a minimum thickness of 3.5 mils (0.089 mm), over an application range of −54 °C to 149 °C. The gas tape industry — including manufacturers that market yellow "full density" tape — uses that same threshold as the full-density reference, although gas-specific certification in the US runs through the UL Component Recognition listing category 31RO, not through A-A-58092 itself. By contrast, standard general-use white tape has no density floor mandated by a standard: manufacturer catalogs report typical values between 0.5 and 0.9 g/cm³ depending on the commercial line, well below the gas tape threshold.

The European gas standard distinguishes by thread class, not only by density

EN 751-3:2022+A1:2023 (unsintered PTFE tapes and strings for metallic threaded joints in contact with 1st, 2nd and 3rd family gases — town gas, natural gas and LPG — and hot water) defines two classes by thread type: class F for fine thread and class G for coarse thread, with test limits up to 500 kPa (≈ 5 bar / 72.5 psi) in gas, 700 kPa (≈ 7 bar / 101.5 psi) in heating hot water, and 20 kPa (≈ 0.2 bar / 2.9 psi) in appliances and their auxiliary equipment. British standard BS 7786:2006, by contrast, covers unsintered PTFE tape for general use — not gas-specific — with mass per area of 25 to 300 g/m² and thickness of 0.05 to 0.25 mm, over a temperature range of −270 °C to +260 °C.

Why this matters in Colombia: the gas installation code requires it

NTC 2505 (residential and commercial gas supply installations) explicitly prohibits hemp and paint as sealant on threaded gas joints, and requires that the PTFE tape used on those joints comply with BS 7786 or MIL-T-27730-A (or the corresponding Colombian technical standard). In commercial practice, that regulatory requirement is not met by just any general-use white tape: it is met by a tape identified and manufactured for that density, commercially the yellow gas tape.

Thickness: the other half of the difference

Besides density, tape thickness also changes with grade: commercial practice reports standard white tape in the 0.075 to 0.09 mm range (3 to 3.5 mils) and yellow gas tape at 0.09 to 0.1 mm (3.5 to 4 mils). The verified factory figure for the yellow line TECTUL distributes (Cellux, codes C-TG-001808 and C-TG-001815) is 100 µm · 0.1 mm, at the high end of that range. TECTUL has no equivalent factory data sheet for the white industrial line (SKU VT-58705): its exact thickness and density are confirmed on quotation.

3. Correct application: direction, turns and when to use tape instead of liquid sealant

Wrap direction and number of turns

The tape is always wrapped in the tightening direction of the thread, never the opposite way: if wrapped backward, the tightening rotation itself unwinds the tape instead of compressing it against the thread crest. Cellux's gas line factory data sheet recommends 3 to 5 turns, adjusted by tape width and thread size; small NPT threads (up to 3/4″) usually need only 2 to 3 turns, while larger threads need more to cover the full engagement. Excess tape does not improve the seal: it acts as a wedge, makes hand-threading harder and can crack the body or female thread on brittle materials (cast bronze, PVC) when the final tightening forces past it.

Leave the first thread free

Leave the first thread — the one closest to the part's end — free of tape: if the tape reaches the edge, tightening can shear off shreds into the bore, which end up as loose debris inside the line. Cover the rest of the thread evenly and press the tape against the crests with your fingers before assembling the joint, so it stays in place and does not shift while threading. Do not reuse tape that already served on another joint: it loses tension and usable thickness.

Tape or liquid sealant: the short rule

Use PTFE tape when the joint will be disassembled with some frequency (maintenance, instrumentation, test lines) and on any gas thread, where the code specifically requires certified PTFE tape or string, not a generic liquid sealant. Use liquid thread sealant when the thread has larger clearances, damaged threads, or when the joint must stay permanently rigid and vibration-resistant without depending on the thickness of a hand wrap. TECTUL's liquid sealant data sheet covers that second product family in detail; this sheet only sets the selection criterion between the two.

4. Frequently asked questions

Does white tape work for gas?

No. Standard-density white tape (typically 0.5–0.9 g/cm³) does not reach the full-density threshold (≥ 1.2 g/cm³) the industry uses as the gas reference, and in Colombia NTC 2505 requires that tape on threaded gas joints comply with BS 7786 or MIL-T-27730-A. For gas, the yellow tape identified for that service is specified, not general-use white tape.

How many turns of PTFE tape should be used?

3 to 5 turns is Cellux's factory recommendation for the gas line, adjusted by tape width and thread size: small NPT threads usually need 2 to 3 turns, larger ones more. More turns than needed do not improve the seal: they act as a wedge and can crack brittle-material parts when tightening forces past the excess.

Does PTFE tape withstand gasoline or diesel?

Yes, PTFE is chemically inert to virtually all industrial fuels, oils and solvents, so the tape does not degrade chemically in contact with them. That alone does not certify the joint for that service: the suitability of the full connection — thread, fitting, tape density required by the applicable code — is confirmed on quotation per the project's standard.

What is the difference between industrial tape and gas tape?

The density of the compacted PTFE, not just the color: yellow is full density (≥ 1.2 g/cm³ reference) and white is standard density (typically 0.5–0.9 g/cm³). Yellow's higher density resists gas permeation through the tape itself better, and it is what the gas installation code requires.

What standard requires PTFE gas tape in Colombia?

NTC 2505, the residential and commercial gas supply installation standard, requires tape conforming to BS 7786 or MIL-T-27730-A (or the corresponding Colombian technical standard) and explicitly prohibits hemp and paint as gas thread sealant. The equivalent gas-specific European standard is EN 751-3.

Can I use yellow gas tape on a water line instead of white?

Technically yes: being higher density, gas tape also seals water, air or oil threads. It is not the usual economical choice — it costs more per roll than white — and in practice it is reserved for gas, leaving white for the rest of compatible general services.

5. Application notes

6. Technical notice and limitation of liability