Import Bolts Heater 1.2311(4)- 18x700 — Buy in wholesale FOB from Supplier in China

The bolts heater 1.2311(4)- 18X700 is a specialised electric heating element designed for thermal tensioning of large bolt assemblies in steam turbines, generators, and heavy rotating machinery. The designation 1.2311(4) refers to the German DIN material grade for a pre-hardened mould steel, indicating a chrome-manganese alloy steel with typical hardness of 28-32 HRC in the annealed condition, though the heating rod itself is typically manufactured from austenitic stainless steel or Incoloy sheathing for oxidation resistance at elevated temperatures. The 18 mm diameter and 700 mm heated length are dimensioned for medium-capacity turbine casing bolts, with a typical power density of 2.5-4.0 W/cm² for controlled, uniform heat expansion. Dongfang Yoyik Engnieering Co., Ltd., based in Deyang, Sichuan Province, lists this part among its turbine and generator spare parts inventory alongside speed sensors, LVDT transmitters, and differential expansion probes.

The heater construction typically comprises a nickel-chromium resistance wire embedded in compacted magnesium oxide insulation within a metallic sheath, terminated with threaded fittings or flying leads for direct bolt insertion. Material grade 1.2311(4) in the product code may denote the target bolt material compatibility rather than the heater sheath composition, which is more commonly 321 or 347 stainless steel for cyclic thermal service. Standard industry practice for bolts heaters specifies sheath temperatures up to 650 °C, with voltage ratings of 220 V or 380 V AC being typical for Chinese power plant applications. The 18 mm diameter permits installation in bolts with minimum bore sizes of approximately 20 mm, allowing adequate clearance for thermal expansion and easy extraction after tensioning. Power output for this geometry typically ranges 1.5-3.0 kW depending on watt density and voltage, though buyers should confirm the exact rating with the supplier as it is not stated in the listing data.

Power plants, turbine overhaul contractors, and heavy equipment maintenance departments are the primary buyers for this component, which forms part of scheduled outage toolkits for steam turbine cylinder disassembly and reassembly. The thermal tensioning process reduces bolt load scatter and eliminates the need for hydraulic tensioners on intermediate-size fasteners. When sourcing from Dongfang Yoyik, buyers should verify whether the heater is supplied with integrated thermocouple for temperature monitoring, the termination type (threaded stud, spade terminal, or plug connector), and whether the unit is rated for continuous duty or intermittent tensioning cycles. The supplier's product range spans EH system pumps, valves, filters, and various sensor technologies, suggesting capability in power plant auxiliary systems rather than primary heater manufacture.

Dongfang Yoyik Engnieering Co., Ltd. is located at 4-3f, Building A, Huashan Platz, Deyang, Sichuan Province, China, postal code 618000. The company operates under a Harbor trust tier with a response rate of 0.00% and an average response time of 0 hours, indicating no verified inquiry responses on record. The listing positions the firm as both manufacturer and trader of industrial products, with a stated specialisation in spare parts for turbines and generators, including EH system pumps, valves, filters, filter elements, and other industrial tools and replacements. The product portfolio referenced in the source description is extensive, covering eddy current sensors, LVDT sensors and transmitters, speed sensors, thermocouples, flame detectors, pressure switches, and various other power plant instrumentation and control components.

The supplier's source description asserts that products and services are quality guaranteed, though no specific quality management system certification (such as ISO 9001) is mentioned in the provided data. The company name suggests an affiliation or naming reference to Dongfang Electric, the major Chinese state-owned power equipment manufacturer headquartered in the same province, but no formal corporate relationship is stated. Buyers should independently verify manufacturing capability versus pure trading status, as the description claims both manufacturer and trader roles without clarifying which items are produced in-house. The supplier's verification status and response performance suggest limited platform engagement, so direct communication to confirm technical support, warranty terms, and documentation availability is advisable before placing orders.