How to calibrate and adjust the safety relief valve on RCB pump?

The built-in high-precision safety relief valve on the RCB pump cover is typically set to open at 1.05 to 1.15 times the rated working pressure. During commissioning, slowly adjust the spring preload until the target cracking pressure is reached, then lock the nut to prevent loosening. When system pressure exceeds this limit, the valve automatically opens to discharge medium back to the suction chamber, protecting the pump gears and downstream piping from high-pressure shock damage. Regular calibration of this valve is a critical step in preventive maintenance.

What are the speed reduction rules for RCB pump when handling high viscosity fluids?

When pumping high-viscosity asphalt or heavy oil, the pump operating speed must be reduced. According to affinity laws, flow is proportional to speed, while power relates to the cube of speed. Maintaining rated speed with high-viscosity fluid causes low suction pressure leading to cavitation and motor overload. It is recommended to control motor speed via a VFD to keep the operating point within the efficiency range. Dynamically adjust speed based on medium viscosity to ensure suction pressure remains above the medium's vapor pressure, preventing air binding.

How to troubleshoot shaft seal leakage on RCB pump?

To troubleshoot shaft seal leakage on the RCB pump, first check the packing gland tightness; standard leakage should be controlled between 30-60 drops per minute. For mechanical seals, verify that the flushing scheme (e.g., Plan 23 or Plan 53) is unobstructed to prevent dry running. In daily maintenance, regularly lubricate packing rings and monitor oil levels. For applications involving asphalt with particulates, dual-face mechanical seals with an isolation liquid system are recommended to extend seal life and eliminate external leakage risks.

RCB SERIES9 modelsHS: 8413.60.29

RCB Jacketed Asphalt Gear Pump (RCB Series)

Hot Oil & Jacketed Asphalt Pumps•RCB

Flow Range: 1.1 ~ 58 m³/h
Pressure Range: 0.28 ~ 1.45 MPa
Motor Power: 1.5 ~ 15 kW
Model: RCB-18.3 → RCB-960
Customs HS Code: 8413.60.29

WhatsApp Quick Quote Email for Price & DrawingModel-by-Model Technical Specifications ↓

RCB Jacketed Asphalt Gear Pump (RCB Series)

Hydraulic Principle & Internal Construction

The RCB series jacketed asphalt insulation gear pump features a double-walled cast casing allowing continuous circulation of thermal oil or saturated steam (up to 0.8 MPa). Designed specifically for road paving bitumen, coal tar pitch, heavy fuel oil, and hot-melt resins, the heated casing prevents fluid solidification during shutdowns and maintains free rotor rotation upon cold startup.

Model-by-Model Technical Specifications

Model	Inlet	Outlet	Flow (m³/h)	Pressure (MPa)	Speed (rpm)	Motor (kW)
RCB-18.3	DN25	DN25	1.1	1.45	960	1.5
RCB-33.3	DN40	DN40	2	1.45	960	2.2
RCB-55	DN40	DN40	3.3	0.33	960	1.5
RCB-83.3	DN50	DN50	5	0.33	960	2.2
RCB-135	DN50	DN50	8	0.33	960	3
RCB-200	DN70	DN70	12	0.33	960	4
RCB-300	DN70	DN70	18	0.36	960	5.5
RCB-483	DN80	DN80	29	0.36	960	7.5
RCB-960	DN100	DN100	58	0.28	970	15

Selection guidance: match your duty point to the closest model below, then confirm with our engineers. Values are rated operating points at the listed speed.

Need Complete Engineering Dimensions & Curves?

Download the official RCB series 1-page technical datasheet covering all 9 model configurations.

Media Compatibility & Viscosity / Temperature Guide

Medium	Max Viscosity (cSt)	Application Note
Paving Grade Bitumen / Polymer-Modified Asphalt	50,000	Heating Jacket ≤300°C
Emulsified Asphalt / Heavy Fuel Oil	30,000	Steam / Thermal Jacketed Tracing
Coal Tar Pitch / Molten Paraffin / Rosin Resins	20,000	Hot Melt Polymers
Soap Glycerin / Crude Glycerol	15,000	Chemical Processing

International Benchmark & Interchange Guide

International Benchmarks

Viking Pump heated/jacketed gear pumps
IMO jacketed internal gear pumps

Interchange Note

Jacketed asphalt bitumen gear pump. Direct drop-in replacement for Viking jacketed 224A/4224A series and IMO jacketed asphalt pumps on road paving equipment.

Materials & Shaft Seal Selection Guide

For the RCB Jacketed Asphalt Gear Pump, pump bodies are recommended in HT250 gray cast iron or QT400-18 ductile iron to withstand thermal jacketing and medium erosion. For corrosive modified asphalt, select 304 or 316L stainless steel. Regarding seals, mechanical seals are preferred for clean asphalt without particulates. If the medium contains tar sludge or requires significant temperature fluctuation tolerance, lubricated packing seals are more reliable. The jacket layer must use high-temperature thermal oil or steam to ensure the asphalt inside remains fluid and prevents gear seizing due to solidification.

Casing & Housing Materials: High-Toughness HT250 Cast IronQT500-7 Ductile Iron (GGG50)Heat-Resistant Cast Steel ZG230-450
Rotor / Gear / Screw Elements: 40Cr Quenched & High-Frequency Induction Hardened GearsCarburized Wear-Resistant Alloy Steel Gears
Shaft Sealing Options: High-Temperature Expanded Graphite Compression PackingWelded Metal Bellows Mechanical Seal

Engineering FAQ

To prevent cavitation on the RCB Jacketed Asphalt Gear Pump, ensure the suction pipe diameter matches or exceeds the rated flow size to minimize velocity. Install a straight run of at least 5 pipe diameters before the inlet to stabilize fluid dynamics and avoid direct impact from elbows. Crucially, calculate the Net Positive Suction Head Available (NPSHa) to ensure it exceeds the pump's NPSHr by a minimum safety margin of 0.5 meters, preventing vaporization of the asphalt medium at the suction side which causes flow interruption and gear damage.

📐 Engineering Selection Methodology

Correct pump selection starts from the fluid, not the pump. Confirm the medium name and actual viscosity at working temperature, the required flow and differential pressure or head, suction conditions (flooded or lift), and whether the fluid crystallizes, shears, contains particles or gas. Positive displacement pumps must always be protected by a relief valve or pressure bypass on the discharge line, and must never be started against a closed valve unless a bypass is fitted. For viscous duties, derate rotational speed to preserve volumetric efficiency; for crystallizing or high-freezing-point media, specify jacketed casings with steam or thermal-oil heating. Our engineers verify each enquiry against these rules before quoting.

🏭 Manufacturing & Quality Control

Castings are produced in our own foundry cluster with material certificates for each heat number. Gear profiles, screw threads and rotor lobes are hobbed, ground and wire-cut to tolerance, then assembled with matched bearing sets. Before dispatch every pump passes casing hydrostatic pressure testing, a run-in test at rated speed on an oil bench, and relief valve cracking-pressure verification; test records are archived against the pump serial number and can be supplied with the shipment.

📦 Export Packaging & Delivery

Pumps are preserved with anti-rust coating, flanges blanked, and packed in export-grade plywood cases with steel strapping for sea freight. Document packs include operating manual, performance test record, packing list and material certificates on request. Standard models ship from stock; engineered configurations typically require 15-35 days depending on casing material and seal options. Spare rotor sets, seal kits and relief valve assemblies can be quoted together with the base pump.

Typical Applications & Industry Use Cases

The media compatibility table above maps directly to real industry duties. In lubrication circuits, size the pump for continuous duty at 70-80% of rated flow to leave margin for viscosity drift as oil warms up. In chemical transfer, confirm the medium's specific gravity and whether it is shear-sensitive before fixing rotational speed. In food and sanitary service, schedule CIP cycles around the product changeover plan and verify elastomer compliance with the relevant food-contact regulation in your market. In hot oil and asphalt service, always pre-heat the casing to the medium temperature before start-up so internal clearances are at operating dimension - a cold start against solidified product is the single most common cause of gear pump failures reported from the field.

Commissioning & Maintenance Guidance

Before first start: verify rotation direction, fill the casing with medium, open the discharge bypass, and jog the motor to confirm free rotation. Check the relief valve setting against the system design pressure and lock the adjuster. During the first hour, record suction and discharge pressures, medium temperature, and motor current - deviations from the quotation duty point usually indicate suction restriction or an over-throttled discharge line. Routine maintenance intervals: inspect the shaft seal weekly during the first month, then monthly; check coupling alignment after any pipe work; drain and inspect the bearing housing annually. Keep a log of running hours so rotors, bearings and seals can be replaced on condition rather than after failure.

Troubleshooting Quick Reference

No delivery or loss of prime: check suction line for air ingress, verify foot valve and strainer are submerged and clean, and confirm the casing is primed for pumps without self-priming capability. Flow below nameplate: verify actual rotational speed against the data sheet, confirm medium viscosity is within the rated band, and inspect internal clearances for wear if the pump has long service hours. Abnormal noise or vibration: usually coupling misalignment, cavitation from excessive suction lift, or foreign matter in the pumping chamber. Seal leakage: confirm flush plan and seal face condition; never run a mechanical seal dry. Motor overload: check for over-viscous medium at start-up temperature and confirm the relief valve is not set above the motor's capability. For anything beyond these basics, send us the serial number and symptom - our engineers will respond with a diagnosis.

📋 Standards, Testing & Documentation

Gear pumps in this catalog are designed and acceptance-tested with reference to JB/T 6434 (external gear pumps), three-screw pumps to GB/T 10886, centrifugal chemical pumps to ISO 2858, and sealless or screw pumps to the relevant API 676 guidance, with mechanical seals supplied to API 682 configurations on request. Sanitary models are manufactured with surface finishes suitable for FDA / 3A style hygienic duties. Each shipment can include: performance test record against the quoted duty point, hydrostatic test certificate, material certificates for pressure-retaining parts, operating and maintenance manual, and a dimensional drawing with flange table. Tell us which standards your project specification cites and we will align the documentation pack accordingly.

🔧 Spare Parts & After-Sales Support

Every pump model page doubles as a spare-parts reference: rotor and gear sets, bearing and thrust assemblies, complete seal cartridges, relief valve kits and jacket gasket sets are manufactured in-house to the same drawings as the original build - so spares ordered years later still match. Recommended commissioning spares are one seal set and one gasket set per pump; for critical continuous-duty installations we recommend a full rotor set held on site. When ordering spares, quote the pump serial number and nameplate data so the correct material and clearance class is supplied. Technical support in English is available by email during China business hours, with video call diagnostics available for installation and commissioning issues.

ℹ️ Technical data on this page is sourced from the manufacturer's engineering database and applicable standards (JB/T 6434, GB/T 10886, ISO 2858, API 676). Final selection must be confirmed by our engineers against your actual duty conditions.

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