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

Install an independent safety relief valve at the pump outlet, as the centrifugal design lacks a built-in one. Set the cracking pressure to 1.05-1.15 times the normal operating pressure. Establish a return flow by slowly opening the bypass valve before adjusting the spring preload. Lock the bolts and verify the reseating pressure to ensure reliable overpressure protection.

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

When fluid viscosity increases significantly, reduce the pump operating speed to prevent motor overload and cavitation. According to affinity laws, flow is proportional to speed and head to the square of speed. Speed reduction also minimizes bearing heat generation. It is recommended to use a VFD to automatically adjust speed based on real-time viscosity feedback for optimal efficiency.

How to troubleshoot shaft seal leakage on RY pump?

When troubleshooting leakage, first check the packing gland tightness; a slight drip is acceptable for lubrication. For mechanical seals, verify that the flushing scheme (e.g., Plan 23) is unobstructed. Routine maintenance includes monitoring bearing temperatures to ensure air-cooled fins are not clogged with oil sludge. Replace seals immediately if abnormal heating or leakage occurs to prevent water mixing.

RY SERIES12 modelsHS: 8413.70.99

RY Air-Cooled Hot Oil Centrifugal Pump (RY Series)

Hot Oil & Jacketed Asphalt Pumps•RY

Flow Range: 3.5 ~ 400 m³/h
Head Range: 15 ~ 85 m
Motor Power: 1.5 ~ 75 kW
Model: RY 20-20-100 → RY 150-125-250
Customs HS Code: 8413.70.99

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

RY Air-Cooled Hot Oil Centrifugal Pump (RY Series)

Hydraulic Principle & Internal Construction

The RY series air-cooled centrifugal thermal oil pump is specifically designed for forced circulation of heat transfer oils up to 350°C without requiring an external water-cooling system. Its extended cooling neck features circular annular radiating fins that dissipate heat via ambient natural convection. High-temperature fluororubber lip seals paired with silicon carbide mechanical seals ensure zero leakage in textile stenters, asphalt mixing, and chemical reactors.

Model-by-Model Technical Specifications

Model	Inlet	Outlet	Flow (m³/h)	Head (m)	Speed (rpm)	Motor (kW)
RY 20-20-100	DN20	DN20	3.5	15	2900	1.5
RY 25-25-160	DN25	DN25	4.5	25	2900	3
RY 32-32-160	DN32	DN32	6.5	32	2900	4
RY 40-40-160	DN40	DN40	11	32	2900	5.5
RY 50-32-160	DN50	DN32	14	32	2900	7.5
RY 65-40-160	DN65	DN40	22	32	2900	11
RY 65-50-160	DN65	DN50	25	32	2900	15
RY 80-50-160	DN80	DN50	50	33	2900	22
RY 100-65-200	DN100	DN65	80	50	2900	37
RY 100-65-250	DN100	DN65	100	80	2900	75
RY 125-100-250	DN125	DN100	200	80	1450	75
RY 150-125-250	DN150	DN125	400	85	1450	75

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 RY series 1-page technical datasheet covering all 12 model configurations.

Media Compatibility & Viscosity / Temperature Guide

Medium	Max Viscosity (cSt)	Application Note
Organic Heat Transfer Oil (High-Temp Carrier)	150	≤350°C, clean fluids without solids
Synthetic Heat Transfer Thermal Fluid	200	Synthetic Fibers & Calendering Line
High-Temperature Heat Transfer Thermal Oil	120	Reactor Thermal Jacket Heating Circuit

International Benchmark & Interchange Guide

International Benchmarks

Allweiler (Germany) thermal oil / hot oil pumps
KSB / Grundfos hot oil pumps
Ruhrpumpen hot oil centrifugal pumps

Interchange Note

Air-cooled high-temperature thermal oil pump (350°C). 100% interchangeable in footprint and hydraulic curve with Allweiler NTT, KSB Etanorm SYT, and SIHI ZTN hot oil pumps.

Materials & Shaft Seal Selection Guide

For the RY pump operating conditions, the casing is recommended to be made of HT250 gray cast iron or QT400-18 ductile iron to withstand 350°C temperatures and thermal shock. If the medium contains trace corrosive components, use 304 or 316L stainless steel for wetted parts. For sealing, packing seals should use high-temperature graphite rings with flexible glands; mechanical seals are recommended as double-faced structures with flushing liquid, preferably using silicon carbide faces and hard alloy sleeves to ensure long-term stability in dry running or high-temperature environments.

Casing & Housing Materials: Heat-Resistant Ductile Iron QT450-10Heat-Resistant Cast Steel ZG230-450
Rotor / Gear / Screw Elements: Investment Cast ZG230 Steel ImpellerQT450 Ductile Iron Impeller
Shaft & Spindle Materials: High-Temp Wear-Resistant Cr-Mo Alloy Steel Shaft
Shaft Sealing Options: High-Temp SiC Bellows Seal + Secondary Backup Heat Packing

Engineering FAQ

Design the suction piping with a velocity between 1.5-2.0 m/s to minimize friction losses. Ensure at least 3 pipe diameters of straight run before the inlet to stabilize flow and avoid turbulence from elbows or valves. Maintain an NPSHa margin greater than 0.5 meters to prevent cavitation caused by temperature fluctuations in the hot oil.

📐 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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