NYP High-Viscosity Internal Gear Rotor Pump (NYP Series)
High-Viscosity Internal Gear Pumps•NYP
- Flow Range
- 0.5 ~ 100 m³/h
- Pressure Range
- 0.6 ~ 1 MPa
- Motor Power
- 1.5 ~ 90 kW
- Model
- NYP-0.78 → NYP-160
- Customs HS Code
- 8413.60.29
Hydraulic Principle & Internal Construction
The NYP high-viscosity internal gear pump utilizes a crescent-type internal rotor and idler gear design. The outer rotor drives the inner idler gear in the same rotational direction, separated by a stationary crescent partition. The expanded tooth chambers gently draw in ultra-viscous fluids (up to 100,000 cSt) without shear degradation. Operating at low speeds (100–500 rpm), it delivers smooth, continuous flow for resins, polymers, polyurethanes, adhesives, and chocolate mass.
Model-by-Model Technical Specifications
| Model | Inlet | Outlet | Flow (m³/h) | Pressure (MPa) | Speed (rpm) | Motor (kW) |
|---|---|---|---|---|---|---|
| NYP-0.78 | DN25 | DN25 | 0.5 | 0.6 | 200 | 1.5 |
| NYP-2.3 | DN25 | DN25 | 1.5 | 0.6 | 300 | 2.2 |
| NYP-7.0 | DN40 | DN40 | 4 | 1 | 400 | 4 |
| NYP-24 | DN50 | DN50 | 12 | 1 | 500 | 7.5 |
| NYP-52 | DN65 | DN65 | 28 | 1 | 600 | 15 |
| NYP-80 | DN80 | DN80 | 50 | 1 | 700 | 30 |
| NYP-110 | DN100 | DN100 | 80 | 1 | 800 | 55 |
| NYP-160 | DN150 | DN150 | 100 | 1 | 960 | 90 |
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 NYP series 1-page technical datasheet covering all 8 model configurations.
Media Compatibility & Viscosity / Temperature Guide
| Medium | Max Viscosity (cSt) | Application Note |
|---|---|---|
| Polyurethane Iso & Polyol Components (Part A/B) | 300,000 | Polyurethane Foam Raw Materials |
| Epoxy Resins / Unsaturated Polyester Resins | 200,000 | Heating Jacket Required |
| Polymeric MDI / Crude MDI (Isocyanates) | 300,000 | Temperature-Controlled Fluid Transfer |
| SBS Modified Bitumen / Asphalt Mastic | 100,000 | Steam/Oil Jacketed Tracing ≤300°C |
| Chocolate Mass / Cane Molasses | 50,000 | Food Grade 316L Stainless Steel |
| Shampoo Cream / Cosmetic Silicone Emulsions | 80,000 | Sanitary Option Available |
International Benchmark & Interchange Guide
International Benchmarks
- Viking Pump (USA) H / HL / K / KK / L / LQ / Q internal gear series
- IMO / Picton internal gear pumps
Interchange Note
Direct equivalent and drop-in replacement for Viking Pump (USA) H, HL, K, KK, L, LQ, and Q internal gear series. Displacements, port orientations, and heating jacket dimensions correspond 1:1 with Viking specifications.
Materials & Shaft Seal Selection Guide
Engineering metallurgy and seal selection advice for corrosiveness and temperature: For non-corrosive ambient fluids, use HT250 gray cast iron or QT400-18 ductile iron. For acidic/alkaline or high-temp media, select 304 stainless steel; strong corrosion requires 316L. For seals, mechanical seals are preferred for standard conditions due to longevity and low leakage. Use cooled packing glands for high temps or particulate media. For food/pharma applications, polish all wetted parts and use EPDM or PTFE seals to prevent contamination.
- Casing & Housing Materials
- HT250 Gray Cast Iron (GG25)QT500-7 Ductile Iron (GGG50)304 / 316 / 316L Stainless SteelTitanium Alloy (Grade 2 / Grade 5)
- Rotor / Gear / Screw Elements
- 40Cr Quenched & Nitrided Rotors304 / 316 Wire-EDM Precision Cut Rotors
- Shaft Sealing Options
- PTFE / Aramid Fiber Impregnated Braided PackingHard Alloy Face Mechanical SealMagnetic Drive Sealless Coupling (Zero Leakage)
Engineering FAQ
Although NYP pumps are positive displacement, high viscosity fluids can cavitate at the inlet. Ensure suction pipe diameter is not smaller than discharge, and maintain at least 5 pipe diameters of straight run before the inlet to stabilize flow. Avoid foot valves; use submergence or priming. Ensure NPSHa exceeds 0.3 meters to prevent vaporization damage to rotors.
📐 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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