Frequently asked questions
The questions that come up most often at enquiry stage — surface preparation, overlap, service temperature, cathodic protection, shelf life, minimum order quantity and samples. Where the honest answer is "it depends" or "we do not hold that", it says so.
Technical
Is petro grease tape the same as petrolatum anti-corrosion tape?
“Petro grease tape”, “grease tape” and “petro tape” can be used as market terms for a petrolatum-based corrosion protection wrap. Zhuohuang's controlled product name is Petrolatum Anti-Corrosion Tape. Confirm the grade, dimensions, service temperature and required outer protection against the applicable TDS before ordering.
What surface preparation do these systems need?
For the petrolatum and microcrystalline wax maintenance systems, St2 hand or power tool preparation is sufficient in the applications stated on the data sheet — remove loose rust, scale, flaking coating and standing water. Abrasive blasting and containment are not required for St2-prepared steel in those applications. For buried pipeline work, prepare to the cleanliness the project specification names; St2 is sufficient for the viscoelastic system. Where a project specification sets a higher preparation grade, that specification takes precedence.
What overlap should be used?
A minimum of 55 % overlap is the figure stated in our petrolatum and wax application procedures, which produces a double-thickness wrap over the whole surface. Polyolefin tapes are spiral-wrapped under controlled tension at the overlap the specification requires. Overlap, tape width and the number of layers are confirmed for each asset.
Can the tape be applied to wet or submerged steel?
The seawater-grade petrolatum tape is formulated for this and is applied to wet or submerged steel without a primer — that is the whole reason the marine system exists, because below the waterline the surface simply cannot be dried. The other systems are applied to steel prepared and free of standing water.
Do these systems shield cathodic protection?
The viscoelastic system is selected specifically where cathodic protection compatibility is required — it cold-flows into the surface profile and bonds continuously, so there is no disbonded void to shield current. For any specific pipeline, confirm the requirement with us and against the project specification before selection.
What service temperature can the materials take?
Petrolatum tape grades run from −20 °C to +50 °C (marine), +55 °C (industrial) and +65 °C (seawater); installation between −5 °C and +45 °C. The viscoelastic tape runs −45 °C to +95 °C. The wax system covers higher-temperature service, with a high-temperature grade available. The exact figure for the grade you need is on that product's technical data sheet, all of which are free to download.
Can a wrapped detail be inspected or repaired later?
Yes — that is one of the practical reasons these systems are chosen for maintenance. The wrap can be cut open, the steel inspected, and the detail re-wrapped locally at the next turnaround, without hot work and without recoating the surrounding area.
Which outer wrap should be specified?
Choose it for the exposure, not for the primary tape. Aluminium foil is the reflective option for above-ground and sunlit assets; PE tape suits normal buried backfill; PP fibre-reinforced tape is selected where soil stress, rocky backfill, directional drilling or handling damage are the governing risks. Where a wrapped detail is fully enclosed with no UV or mechanical exposure, an outer wrap may not be needed at all.
Documents and compliance
Are your products certified to AWWA C217, EN 12068 or ISO 21809-3?
No. We hold laboratory test reports measuring properties using those method sets — the wax tape was tested against the ASTM and AWWA C217 method set, and the viscoelastic system against GB/T 23257-2017 — but we do not hold conformity declarations issued by a certification body for those product standards. The standards page lists exactly what is held and what is not, along with what we can offer instead.
Are you an ISO 9001 certified manufacturer?
We hold ISO 9001, ISO 14001 and ISO 45001 certificates, and we publish the certificate numbers and the certified scope exactly as printed. That scope covers the sale of anti-corrosion and wear-resistant materials, coatings, sealing components and fire-stopping materials — it does not cover manufacturing. So we do not describe ourselves as an "ISO-certified manufacturer". If your specification requires certification of manufacturing activities, confirm the required scope wording with us before tender submission.
Do you have SGS, BV, DNV or Lloyd's test reports?
Not at present. All current reports are from CMA / CNAS accredited laboratories in China, which hold ILAC-MRA recognition. Some international tenders will not accept these, and it is better you know that now — testing at an international laboratory can be arranged at project cost if your tender requires it.
Can you supply safety data sheets?
For three products: the petrolatum anti-corrosion tape, the microcrystalline wax tape and the wax corrosion-inhibiting primer. Safety data sheets for the remaining products are a known gap rather than something we will improvise, and we will tell you so rather than issue a document we cannot stand behind.
Ordering and supply
What is the minimum order quantity?
It is confirmed per enquiry rather than published, because it depends on the product mix, the roll and carton configuration and whether packaging is standard or private label. Send the product list and quantity and we will confirm the minimum order quantity, lead time and container loading in writing with the quotation.
Can I get samples before ordering?
Yes. Trial and sample quantities are supplied before a first order so the material can be tested on your own asset. Tell us the substrate and the detail you intend to trial it on and we will send the appropriate grade rather than a generic sample.
Do you produce under our own brand?
Yes — OEM and private-label production, with configurable roll widths, roll lengths, carton quantities and labelling. See the export and OEM page.
Which regions do you supply?
Southeast Asia, the Middle East, Africa and North America, alongside the domestic Chinese market. Enquiries are answered in English or Chinese, and all product documentation is issued in English.
How do I get a system recommendation?
Send asset type and dimensions, existing coating and corrosion condition, operating and installation temperature, exposure (buried, immersed, splash zone or atmospheric), mechanical exposure and backfill, whether cathodic protection is present, any applicable specification, and the estimated quantity and required date. Photographs help more than anything else. That is enough for us to propose a configuration and issue the supporting documents.
Question not answered here?
Send it with the asset details. Technical questions are answered by the people who configure the systems, not by a call centre.