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

The YCB pump is typically equipped with an internal relief valve or external bypass loop. Set the cracking pressure between 1.05 and 1.15 times the rated working pressure to balance system protection and efficiency. To adjust, loosen the locking nut, use a specialized tool to fine-tune the spring preload until the target opening pressure is reached, then retighten and test the reseating pressure. For higher pressures, consider replacing with a larger specification valve or adding an external bypass loop.

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

When handling fluids with viscosity exceeding recommended limits (e.g., >150 cSt), the pump operating speed must be reduced. High viscosity causes a sharp increase in suction resistance, leading to cavitation and air ingestion. According to affinity laws, flow is proportional to speed; therefore, using a VFD to reduce motor frequency from 50Hz to 30-40Hz matches fluid characteristics while effectively reducing heat generation in bearings and gears, extending equipment life.

How to troubleshoot shaft seal leakage on YCB pump?

When troubleshooting shaft seal leakage on a YCB pump, first observe the leak pattern: if it is dripping and manually adjustable, it usually indicates packing gland tightening is needed; if it is jetting, mechanical seal failure is likely. For daily maintenance, the packing gland should allow 0.5-1mm clearance to prevent overheating and be lubricated regularly with grease. For fluids containing particles, use double mechanical seals with a flushing scheme (e.g., Plan 23) to prevent debris from entering the friction pair.

YCB SERIES11 modelsHS: 8413.60.21

YCB Double-Circular-Arc Gear Oil Pump (YCB Series)

External Gear Pumps•YCB

Flow Range: 0.6 ~ 80 m³/h
Pressure Range: 0.6 ~ 1.6 MPa
Motor Power: 0.75 ~ 45 kW
Model: YCB-0.6 → YCB-80
Customs HS Code: 8413.60.21

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

YCB Double-Circular-Arc Gear Oil Pump (YCB Series)

Hydraulic Principle & Internal Construction

The YCB series incorporates advanced double-circular-arc gear meshing geometry. Unlike traditional involute gears that suffer from hydraulic entrapment and tooth-surface sliding, the circular arc profile achieves pure point-to-line contact without fluid trapping. This design virtually eliminates hydraulic pulsation, lowers operating noise to under 68 dB(A), and extends gear service life by more than 300%.

Model-by-Model Technical Specifications

Model	Inlet	Outlet	Flow (m³/h)	Pressure (MPa)	Speed (rpm)	Motor (kW)
YCB-0.6	DN25	DN25	0.6	0.6	960	0.75
YCB-1.0	DN25	DN25	1	0.6	960	0.75
YCB-1.6	DN32	DN32	1.6	0.6	960	1.1
YCB-2.5	DN40	DN40	2.5	0.6	960	1.5
YCB-4	DN40	DN40	4	0.6	960	2.2
YCB-6	DN50	DN50	6	0.8	1150	3
YCB-10	DN65	DN65	10	0.8	1150	4
YCB-16	DN65	DN65	16	1	1450	7.5
YCB-25	DN80	DN80	25	1	1450	11
YCB-40	DN100	DN100	40	1.6	1450	22
YCB-80	DN150	DN150	80	1.6	1450	45

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 YCB series 1-page technical datasheet covering all 11 model configurations.

Media Compatibility & Viscosity / Temperature Guide

Medium	Max Viscosity (cSt)	Application Note
Lube Oil / Heavy Fuel Oil / Hydraulic Oil	1,500	Low Pulsation & Whisper-Quiet Operation
Industrial Gear Oil / Diesel Fuel	1,200	Marine & Long-Distance Pipeline Duty
Heat Transfer Thermal Oil (Cold/Ambient)	500	High-Temp Configuration ≤300°C

International Benchmark & Interchange Guide

International Benchmarks

IMO AB arc-tooth gear pumps
Busch (Germany) rotary gear pumps

Interchange Note

Double circular arc gear pump. Upgrades traditional involute gear pumps (KCB/2CY) to eliminate pulsation, reducing noise and vibration across fuel, diesel, and oil transfer systems.

Materials & Shaft Seal Selection Guide

For YCB pump bodies, gray cast iron (HT250) is suitable for ambient mineral oils and hydraulic fluids, offering low cost but moderate corrosion resistance; ductile iron (QT450-10) provides higher strength for heavy-duty applications. For corrosive media or high-temperature environments, 304 stainless steel or 316L stainless steel is recommended, with the latter offering superior chloride ion resistance due to molybdenum content. Regarding sealing selection, skeleton rubber mechanical seals are suitable for clean fluids; if the medium contains solid particles or requires dry running protection, double mechanical seals with flushing liquid or packing glands with grease injection ports are recommended to ensure long-term reliable operation of the shaft seal.

Casing & Housing Materials: QT600-3 Ductile Iron (GGG60)304 / 316 Stainless SteelCast Steel (WCB)
Rotor / Gear / Screw Elements: Double Circular-Arc Sinusoidal Nitrided Alloy Gears
Shaft Sealing Options: Precision Mechanical SealHigh-Temperature Welded Metal Bellows Seal

Engineering FAQ

To prevent cavitation in the YCB pump, ensure the suction pipe diameter matches or exceeds the inlet flange size to minimize flow velocity. Install at least 5 pipe diameters of straight run before the inlet to stabilize the flow field and avoid direct connection with elbows or valves. Additionally, maintain the installation height within the allowable suction lift limit, reserving a safety margin of at least 0.5 meters for NPSHa to ensure inlet pressure remains above the fluid's vapor pressure.

📐 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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