A: We accept T/T and L/C payment terms, other payment terms can be negotiated. T/T is our most common payment term: 30% deposit before production, 70% balance before shipment. After receiving deposit, we arrange raw material purchasing and start production. Before shipment, we send finished product photos, QC inspection report and packing photos, after receiving balance payment, we arrange shipment and send original shipping documents. Irrevocable sight L/C is acceptable for large bulk orders, especially for customers in countries with strict foreign exchange control. Our bank accepts L/C issued by reputable international banks, we will check L/C clauses carefully before acceptance. For long-term cooperative customers with good credit, we can discuss more flexible payment terms. All payment terms will be written clearly in formal sales contract. We only accept payment to our official company bank account, we do not accept private account transfer for bulk export orders. We provide official bank receipt and commercial invoice after receiving payment.

A: Our quotation for Chuanli cold room electric defrost tube remains valid for 30 days from quotation date. The price may fluctuate with raw material price change of stainless steel, alloy heating wire and high temperature insulation material. Metal raw material price changes frequently in global market. If raw material price rises sharply after quotation expires, we need to update product price. Within 30-day validity period, we guarantee the quoted unit price once you issue formal purchase order. When quotation expires and you still want to place order, we will recheck raw material price and exchange rate, and send renewed quotation. Our formal quotation includes unit price, MOQ, lead time, payment term, packing specification, price term and validity period. For long-term framework customers, we can sign annual price locking agreement to stabilize price within agreed range. When you receive quotation, you can ask our sales team to explain price composition including raw material cost, processing cost and packing cost.

A: Yes, we own professional R&D team for heating element, we can develop new types of cold room electric defrost heating tubes according to your requirement. Our R&D team can design special bent geometry, adjust power density, optimize cold zone structure, select different sheath material and lead wire type to match new evaporator design. The whole development process includes requirement analysis, 2D/3D drawing design, prototype manufacturing, electrical safety test, cyclic heating endurance test and small batch trial production. We can optimize design to improve moisture resistance, anti-corrosion performance and extend service life for special cold room environment. After prototype passes all lab tests, small batch trial production can be arranged to verify mass production feasibility. We can sign non-disclosure agreement to protect your new product design, we will not sell this newly developed defrost tube to third parties without your authorization. New product development needs certain development cost and development cycle, our sales team will inform you estimated timeline and cost before project launch.

A: For customization of cold room electric defrost tube, you can offer engineering drawings, physical sample or detailed technical parameters, then our team will evaluate and quote accordingly. If you have existing old defrost tube sample, sending physical sample is most convenient, our engineers can measure dimension, bending shape, heating length, cold zone length, power and lead wire style. If you have CAD drawing, please provide full dimension, tube diameter, bending shape, heating section length, cold zone length, rated voltage, rated power, lead wire length and connector type. If no drawing or sample, you can fill our technical requirement sheet, including evaporator installation space, required defrost power, working voltage, mounting method and cold room environment (humidity, corrosive condition). After receiving your information, our R&D engineer will carry out technical evaluation, check feasibility, calculate cost and lead time, then send you technical proposal and quotation. We will point out potential risk and optimization suggestion for power density and cold zone design. After you confirm technical plan, we produce prototype sample for your test. All customized technical documents will be kept confidential.

A: MOQ for standard Chuanli cold room electric defrost tubes: XX pcs; MOQ for customized defrost tubes: XX pcs. MOQ is determined based on raw material cutting, tube bending fixture cost and production setup work. For standard straight, U and M shape defrost tubes, we maintain inventory, so MOQ is relatively low, suitable for cold room maintenance companies and small engineering orders. For customized defrost tubes with special bending shape, we need to make custom bending mould, adjust production setup, which brings extra cost, so customized MOQ is higher. If your quantity is less than customized MOQ, we can discuss simple OEM solution such as printing your logo on standard products with lower MOQ. If you sign long-term annual purchasing framework, we can negotiate lower MOQ for continuous orders. Mixed order of multiple standard specifications is acceptable as long as total quantity meets MOQ requirement. Our sales team will clearly state MOQ, unit price and lead time in formal quotation. We will remind customers that once customized production starts, changing shape or parameters will cause extra cost and delivery delay.

A: Yes, we accept OEM and ODM service for Chuanli cold room electric defrost tubes. We can customize logo, nameplate, tube length, power, voltage, bending shape, lead wire type and export packaging according to your requirement. OEM service includes printing your brand logo on product label and outer carton, so you can sell defrost tubes under your own brand without building production workshop. ODM service means we design new shape and specification defrost tube according to your evaporator structure and defrost requirement. Our R&D team can design special bent shape, adjust cold zone length and power density to match your evaporator. We can customize outer carton, color box and user manual with your brand information. Before mass OEM/ODM production, we will make pre-production sample for your confirmation, only after sample approval we start mass production. We will strictly keep your brand information and customized design confidential, and will not disclose your customized specification to other customers. We have rich OEM cooperation experience with many overseas refrigeration spare parts suppliers and cold room equipment manufacturers.

A: Samples and mass production Chuanli electric defrost tubes adopt the same raw material standard, production craft and finished inspection standard, so quality consistency is fully guaranteed. We do not use separate production line only for samples. The sample is produced from same production line and same raw material batch as bulk products. Raw material specification, tube bending process, powder filling, welding sealing and electrical safety test criteria are fully identical. Before sample delivery, we carry out the same full inspection items as bulk products: insulation resistance test, high voltage withstand test, continuity test and appearance inspection. Each sample has unique production batch record. When mass production starts for your bulk order, our QC team follows identical inspection checklist. You can arrange third-party inspection for bulk goods before loading, and compare bulk product with your reference sample. If any quality inconsistency is found between sample and bulk shipment, we will actively negotiate solution according to contract. Batch quality consistency is our core advantage as professional heating element manufacturer, we strictly avoid the common problem "good sample, bad bulk" in international sourcing.

A: Standard electric defrost tube samples will be ready within 3–7 working days after sample payment is confirmed. The buyer bears the shipping cost of samples. For standard samples in our warehouse, we can finish QC inspection, packing and arrange shipment within 3–7 working days. For customized prototype samples with special bending shape or parameters, the production time will be longer, we will inform you exact lead time before sample order. The sample freight cost depends on sample weight, volume and destination country. We can help you collect freight quotation from multiple forwarders for your reference, or you can use your own freight forwarder to pick samples from our factory. We will prepare full export documents including commercial invoice and packing list for sample customs clearance. We use shockproof carton for sample packing to avoid bending damage during transit. Before shipment, we take photos of packed samples for your confirmation. The buyer is responsible for destination import customs clearance and import tax. If you have special requirement for shipping mark or document format, we can adjust accordingly.

A: Yes, we can supply Chuanli cold room electric defrost tube samples for your installation test and performance verification. The sample cost will be fully refunded when you place formal bulk order. For cold room engineering companies and evaporator manufacturers, sample test is necessary to check dimension matching, installation adaptability and heating performance before mass procurement. You can select standard shape and specification samples from our stock. If you need customized bent shape or special power defrost tube sample, we can produce prototype sample, with different sample lead time and sample cost. After sample arrives, you can install it on your evaporator to test defrost effect, heating uniformity and insulation safety. Our technical team can provide remote technical guidance for sample installation and test. Please note that sample is only for technical verification, sample warranty rule is different from bulk goods. When you confirm bulk order later, sample cost will be deducted directly from bulk payment. This policy reduces your pre-investment risk for product verification. Before sending samples, we carry out full electrical inspection including high voltage test and insulation resistance test, pack samples with anti-pressure carton, and send test report together with samples. We can also take packing photos and test video before shipment.

A: Chuanli cold room electric defrost tube has long service life under normal operating conditions in cold room evaporator environment, and we can provide performance test report. The alloy heating wire can work stably under cyclic heating and cooling. The stainless steel sheath can resist the frost water and humid environment inside cold room evaporator. Standard SUS304 sheath fits most ordinary cold storage. SUS316L customized version offers stronger corrosion resistance for high humidity or slightly corrosive environment such as seafood cold warehouse. The high temperature silicone sealing material can resist temperature change from sub-zero cold room temperature to defrost heating temperature repeatedly. Service life is closely related to working condition, power density, installation method and defrost cycle setting. If installed correctly, power matches evaporator requirement and defrost control system works normally, the defrost tube can reach designed service life. Improper installation, too high power density, frequent overheating or water immersion will shorten service life and cause burnout. Our performance test report includes high voltage withstand test, insulation aging test, cyclic heating-cooling endurance test and salt spray corrosion test. Our technical team can provide installation guide and power matching suggestion to extend service life and reduce failure rate. We will mark working limit parameters in product manual and remind forbidden working conditions.

A: Chuanli cold room electric defrost tube is mainly used for evaporator defrosting of cold storage, walk-in freezer, commercial freezer and refrigeration equipment. It is the core heating component for electric defrost system of cold room air cooler. In low-temperature cold room, water vapor will condensate and form thick frost layer on evaporator fin surface. Thick frost will block air flow, reduce heat exchange efficiency, increase compressor load and waste energy. The electric defrost tube is installed on evaporator coil, when defrost cycle starts, the tube generates heat to melt frost and ice layer on fins, melted water flows out through drain pan and drain pipe. After defrost finished, refrigeration system restarts and continues cooling. This electric defrost method is simple, stable and widely adopted in medium and small cold storage, food preservation cold room, meat freezer, supermarket refrigeration cabinet and ice maker. Different cold room types have different defrost power requirement. Large industrial cold room evaporator needs higher power defrost tubes; small commercial cold room uses low power heating tubes. Our technical team can assist model selection according to your cold room volume, evaporator size, working temperature and defrost cycle setting. We have many reference project cases for cold room engineering contractors. If you are refrigeration equipment manufacturer, we can design matched defrost tube for your evaporator product.

A: We supply multiple standard sizes, power rating, voltage and shape options for Chuanli cold room electric defrost tubes, and customized specifications are available according to customer installation requirement. Our standard product portfolio covers straight tube, U-shape, M-shape and special bent shape defrost tubes, which are widely installed on cold room evaporator air cooler. We have different tube diameter options, various total length, heating section length, cold zone length, rated power and rated voltage, including 110V, 220V and other voltage options for different countries. The cold zone (non-heating section) is specially designed to protect the wire terminal from overheating damage, which is very important for evaporator installation. Many customers need custom length, power, lead wire length and terminal connector type to match their existing evaporator fin coil. Our technical team can assist model selection: you only need to provide evaporator dimension, required defrost power, installation space and voltage, we will recommend suitable specification. If our standard products cannot fit your evaporator structure, we can make customized bending shape, adjust heating power and cold zone length. Before mass customized production, we will make prototype sample for your installation test. We can provide full parameter sheet, dimension drawing and installation manual for all defrost tube models. Wrong specification selection will cause insufficient defrost effect or overheating burnout, our engineers can help you avoid such risk.

A: Chuanli cold room electric defrost tube is made of high-quality stainless steel sheath tube and high-temperature resistance alloy heating wire, filled with high purity magnesium oxide powder for insulation, with stable heating performance and good moisture resistance in cold room low temperature and high humidity environment, and we support material inspection. The outer sheath uses SUS304 stainless steel as standard option, SUS316L stainless steel is available for anti-corrosion customized requirement. SUS304 stainless steel has good anti-rust performance for ordinary cold room environment, resist frost water and humid air inside evaporator. SUS316L is selected for cold storage with weak corrosive gas, such as seafood cold room, to improve corrosion resistance and extend service life. The internal heating wire is nickel-chromium alloy wire, which has stable resistance and long service life under cyclic heating and cooling in repeated defrost cycles. High purity magnesium oxide powder filled between heating wire and metal sheath has excellent insulation and thermal conductivity, transfer heat quickly and prevent electric leakage. The terminal sealing part adopts high temperature silicone sealant to prevent moisture and frost water penetrating into tube inside, which is critical for cold room evaporator working environment with frequent frost and melting water. Poor quality defrost tubes use low grade iron tube or impure magnesium oxide powder, which easily cause electric leakage, burnout and short circuit. We can provide material composition test report for customers. Our technical team can recommend suitable sheath material according to your cold room environment, humidity and corrosive condition.

A: Sure, factory visit can be arranged by advance appointment. We welcome procurement managers, refrigeration engineers and quality inspectors from global cold storage industry to visit our factory. Please contact our sales team in advance to inform visiting date, visitor quantity and your inspection focus, such as production line, electrical safety testing lab, raw material warehouse or finished goods storage. During factory tour, our technical team will show you the whole production process of cold room electric defrost tube: stainless steel tube cutting, heating wire assembly, magnesium oxide powder filling, tube shrinking, welding sealing, lead wire connection and electrical performance testing. You can see our high voltage withstand test and insulation resistance test on testing bench, and check raw material quality. You can also see different finished defrost tube samples with different shapes, power and length. Our engineers can explain key technical points about defrost tube working principle, power density design and anti-moisture sealing technology for cold room low temperature environment. For overseas customers who cannot travel to China, live video factory visit is available, we can show workshop and testing lab in real time and answer your questions online. Factory visit helps buyers verify our manufacturing strength, check quality control level and build long-term cooperation trust. After your factory tour, we can summarize technical discussion record for your team.

A: Our annual production capacity reaches XX pieces for Chuanli cold room electric defrost tubes, and we can fulfill large bulk orders for cold room projects and refrigeration equipment manufacturers. We have multiple automatic production lines for tubular heating elements, with stable daily output. We keep safety stock for standard defrost tube specifications, including different length, power, voltage and shape such as straight type, U type, M type defrost tubes widely used in cold room evaporator. For large bulk orders, our production scheduling team will arrange production plan in advance, arrange raw material purchasing of stainless steel tube, high temperature magnesium oxide powder and alloy heating wire. We have stable raw material suppliers for heating element raw materials, which can avoid production interruption caused by raw material shortage. For long-term framework customers, we can reserve production capacity in advance to guarantee delivery. Our production team can produce thousands of pieces per month for standard models. We can make production progress report for large orders, update production status regularly for buyers to track order progress. Whether you need one-time big bulk shipment for cold room construction project or recurring monthly replenishment for spare parts sales, our factory capacity can meet your demand steadily. We can also adjust production schedule to rush order for urgent cold room projects.