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Zhejiang Sanli Pipe Technology Co., Ltd.
Pipe Buying Guides & FAQ for Importers
SANLI Underfloor-Heating Knowledge Base

Pipe Buying Guides & FAQ for Importers

Selection, factory-audit, logistics and pricing guides for importers, buyers and contractors worldwide (updated regularly).

Industry

Read the market and your supplier: export markets & trends, factory audits, EAC/ISO/CE, duty & customs, Incoterms & pricing.

WP·01

Central-Asia heating & plumbing pipe market 2026

Demand drivers, channel structure and import substitution — a stocking and pricing reference for distributors.

White paper · planned
WP·02

Exporting to the EAEU: EAC/GOST compliance & procurement

Certification path, documentation and customs essentials for compliantly sourcing Chinese-made pipe.

White paper · planned
01

How to Verify a Chinese Pipe Factory Before You Order: A 10-Point ChecklistProcurement & compliance

From business licence and certificate numbers to per-coil inspection: 10 checks that filter out a risky supplier before you pay a deposit.

Read article →03

EAC, GOST, CE, ISO, SKZ: Which Certificates You Actually NeedProcurement & compliance

Legal market access versus commercial trust signals: what EAEU customs, tenders and specifications really require.

Read article →04

How to Choose a PEX-AL-PEX Pipe Factory: Lead Time, Price and OEM FlexibilityProcurement & compliance

Big brand factory or responsive mid-sized one — for many orders lead time, real price and OEM options matter more than the name printed on the coil.

Read article →05

A Landscape of Leading Chinese Pipe Makers: Lesso, Kingbrand, Rifeng, VASEN, SANLI and FengfanProcurement & compliance

Six manufacturers in one table — product range, positioning, markets and genuine strengths; no overall winner, just the right fit for your order.

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Import duty & landed cost for Central Asia: HS codes, VAT and how to estimateProcurement & compliance

How heading 3917 drives customs duty and VAT in EAEU countries and Uzbekistan, and how to build a full landed-cost figure.

Read article →01

What drives PEX-AL-PEX and underfloor-pipe prices in 2026Procurement & compliance

From oil, LME aluminium and USD/CNY to rail freight into Central Asia — how to read a 2026 pipe quote

Read article →02

EXW vs FOB vs CIF vs DDP vs FCA/CPT: choosing terms for Central AsiaProcurement & compliance

Who pays freight, insurance and customs, where risk transfers — and why FCA and CPT matter most for landlocked buyers

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How to write an RFQ that gets a fast, accurate wholesale quoteProcurement & compliance

The ten fields a real RFQ needs — series, SDR, barrier class, EAC, OEM, incoterm, tiers — plus a 1-minute form

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EAC-Certified PEX-AL-PEX Pipe for Russia & Kazakhstan — What Importers Must CheckProcurement & compliance

What EAC / TR TS conformity means for pipe, why it gates customs and tenders, what our certification covers and how to verify a supplier's document

Read article →

Products

PEX-AL-PEX, PE-RT, PP-R and brass fittings — OEM, MOQ and container-loading plans from one factory.

WP·01

Brass fitting corrosion and water-quality compatibility

Dezincification, chlorides and hard water: material selection and protection for different water chemistries.

White paper · planned
02

MOQ, Samples and Payment Terms: How to Buy Pipe from China Without Getting BurnedProcurement & compliance

Typical MOQ per SKU, sample policy, T/T 30/70, irrevocable L/C and escrow — and where the buyer keeps leverage.

Read article →02

Container loading: how to estimate CBM and metres per containerSelection & technical guides

Pipe is light and bulky, so a container fills up by volume, not weight. A practical method for 20GP / 40GP / 40HQ.

Read article →04

OEM & Private-Label PEX-AL-PEX Pipe — Your Brand From 10,000 mProcurement & compliance

What a factory can run under your name: pipe, PE-RT/EVOH barrier pipe, brass fittings and manifolds — with logo marking, colour choice and insulation

Read article →

Technology

Material science and engineering: PEX vs PE-RT, oxygen barrier & DIN 4726, temperature and pressure, sizing, loops and layout.

WP·01

PEX-AL-PEX vs PE-RT: a life-cycle cost white paper

Total cost over a 50-year design life — purchase, installation, maintenance and rework — not price per metre.

White paper · planned
WP·02

Reliability of multilayer pipe in cold-climate underfloor heating

How freeze–thaw cycles, thermal expansion and joint method affect long-term sealing, with engineering guidance.

White paper · planned
01

Which pipe for heating and hot water: PEX-AL-PEX vs PE-Xa vs PE-RT vs PP-RSelection & technical guides

Four materials compared by temperature, pressure, oxygen permeation, installation and price — plus what to stock.

Read article →02

Why the oxygen barrier matters: EVOH vs aluminium layer and diffusion corrosionSelection & technical guides

How oxygen diffusing through the pipe wall destroys boilers, radiators and manifolds — EVOH vs a 100 % aluminium barrier per DIN 4726.

Read article →03

Sizing & standards: SDR, PN, wall thickness and common pipe dimensionsSelection & technical guides

What SDR and PN really mean, how they map to pressure and temperature, and which sizes and coil lengths to specify for underfloor heating.

Read article →04

PE-Xa / PE-Xb EVOH Oxygen-Barrier Pipe: Structure and How It WorksSelection & technical guides

Cross-linked polyethylene, the 3-D network and the outer EVOH oxygen barrier — what the pipe is made of and why it works

Read article →01

How many metres of underfloor-heating pipe do you need?Selection & technical guides

A simple formula using heated area, laying pitch and loop count, so you order the right quantity of PEX/PE-RT coil.

Read article →

Glossary

Key pipe-industry terms and standards (PEX-AL-PEX, PE-RT, EVOH, DIN 4726, PN/SDR, EAC/GOST) in one place.

PEX-AL-PEX (multilayer pipe)
Five layers: PE-X / adhesive / welded aluminium / adhesive / PE-X. The aluminium layer gives a 100% oxygen barrier, low thermal expansion and shape retention. Standards: EN ISO 15875, GOST R 52134.
PE-RT (polyethylene of raised temperature)
Thermoplastic polyethylene; heat-fusible and recyclable, very flexible and easy to coil — cost-effective for low-temperature underfloor heating. Standards: EN ISO 10508 / GOST 32415.
PE-Xa / PE-Xb (cross-linking method)
Distinguished by cross-linking method: PE-Xa is peroxide (Engel) cross-linked (~70–87% degree, with a memory effect), PE-Xb is silane cross-linked. Cross-linking raises heat and pressure resistance but rules out heat fusion — use press or slide-sleeve joints.
EVOH (oxygen-barrier layer)
An ethylene-vinyl alcohol layer co-extruded onto the pipe wall to stop oxygen diffusing into closed heating systems, meeting DIN 4726; usually covered by a protective outer layer.
DIN 4726
The German standard limiting oxygen permeation through plastic heating pipe (to roughly <0.325 g/m³·day) so that steel and copper components in the system are protected.
PN (nominal pressure)
Nominal Pressure — the design working-pressure class referenced to 20 °C (e.g. PN10, PN20). The allowable pressure falls as temperature rises and must be derated for the duty.
SDR (standard dimension ratio)
The ratio of outside diameter to wall thickness (SDR = dn/en). A lower SDR means a thicker wall and higher pressure rating; SDR and PN together set the rating.
Press fitting / slide sleeve
A stainless-steel or brass fitting compressed cold with a dedicated tool to form a seal — no heat fusion required; the standard jointing method for PEX and PE-RT.
Manifold
A brass or stainless-steel assembly that distributes the heat-transfer fluid to the heating loops and collects the return, often with flow balancing and thermostatic heads.
Oxygen corrosion
Oxygen diffusing through the pipe wall into a closed loop corrodes the boiler heat exchanger, steel radiators and brass parts — a leading cause of wet-system failure. An oxygen barrier largely prevents it.
See full glossary →

FAQ

Quick answers to the questions buyers ask most before ordering.

What is the difference between PEX-AL-PEX and PE-RT pipe, and which is better for underfloor heating?
SANLI PEX-AL-PEX composite pipe has an aluminium layer that blocks oxygen and cuts thermal expansion, so it holds its shape and suits heating loops and radiators. PE-RT from China manufacturer SANLI is flexible, heat-fusible and lower cost, making it a good fit for low-temperature underfloor heating. For standard water-based UFH choose PE-RT, and for higher temperature or stiffer runs choose PEX-AL-PEX.
Do I need an oxygen-barrier pipe for underfloor heating, and why?
Yes, a closed water heating system needs an oxygen-barrier pipe because oxygen ingress corrodes boilers, manifolds and steel parts. SANLI supplies PE-Xa and PE-RT pipe with a 100% oxygen barrier meeting DIN 4726. This protects the plant and extends the service life of the underfloor heating.
What temperature and pressure can these pipes handle?
SANLI underfloor-heating pipes are typically rated for a working temperature of about 60-70 °C and short-term peaks up to roughly 90-95 °C. Working pressure depends on the PN class and pipe size, commonly 6-10 bar for heating. Confirm the exact temperature and pressure ratings for your design from the SANLI technical data sheet.
What is the maximum coil or loop length without joints?
SANLI supplies PEX-AL-PEX and PE-RT pipe in coils up to 100 m with no joints, cutting the number of connections under the floor. The maximum single loop length depends on diameter, typically up to about 100-120 m for 16 mm and shorter for larger sizes. These figures are indicative, so confirm the exact loop length with SANLI for your project.
What is your minimum order quantity (MOQ)?
The standard SANLI MOQ is about 1,000 metres per pipe specification, and mixed containers with different diameters and colours are welcome. Samples and pallets follow separate terms. Confirm the exact MOQ in metres in your quote.
Can you OEM or private-label the pipe?
Yes, as a China manufacturer with 20+ years and 20 production lines, SANLI offers OEM and private-label work: your brand printing, custom pipe colour, labels and pallets. Branded products carry their own MOQ. Confirm the printing details and minimum batch with SANLI.
Do you provide free samples?
SANLI provides free pipe and fitting samples so buyers can assess the quality. The buyer only pays the courier freight. Request samples carrying SANLI marking to verify the material.
Which payment terms do you accept?
SANLI normally works on T/T with 30% deposit and 70% balance before shipment, and also accepts sight L/C. Trade Assurance is available for a first order to protect the transaction. Final payment terms are confirmed in the contract.
How long is the production lead time?
The standard SANLI production lead time is roughly 15-25 days after the deposit, depending on volume and specification. During the peak heating season the 20 lines run fuller, so the time can extend. Confirm the exact lead time for your quantity and season.
Which Incoterms do you quote and can you ship to Central Asia?
As a China manufacturer, SANLI ships on EXW, FOB Ningbo, FCA, CPT and DAP terms. Rail delivery to Almaty or Tashkent takes roughly 18-30 days, indicative. Confirm the exact route, transit time and Incoterm for your destination in the quote.
What certifications do your pipes have?
SANLI pipes are certified to ISO 9001, ISO 14001 and ISO 45001, carry CE and SKZ marking for European requirements, and hold EAC certification for the EAEU market. The full document set is available on request. Ask SANLI for the current certificate copies.
Is EAC certification required to sell in Kazakhstan or Russia?
Yes, selling pipe in Kazakhstan, Russia and other EAEU countries requires TR EAEU conformity and an EAC declaration or certificate. As a China manufacturer, SANLI supplies EAC-marked product for this market. Confirm the exact conformity form for your HS code when ordering.
What is the approximate price per metre?
SANLI pipe pricing is roughly in the range of about USD 0.3 to 1.5 per metre, depending on PEX-AL-PEX or PE-RT type, diameter and order volume. Larger batches and mixed containers lower the price per metre. This is an indicative band, so confirm the live rate with a current quote.
How do I estimate how many metres of pipe I need for a project?
Divide the heated floor area by the pipe pitch and add a allowance for the feed runs: metres = area / pitch + waste. For example, 100 m² at a 0.15 m pitch gives about 667 m plus 10-15% for tail and header runs. Use the SANLI knowledge calculator page for a quick estimate.
What is the warranty and how is quality controlled?
SANLI rates its pipes for a service life of up to 50 years when used within specification, with a warranty per product type. Quality is backed by 26 inspection steps and a per-coil test before shipment across 20 production lines. Confirm the warranty terms for your specification in the contract.

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