Nexa Series

Summary

Product identification

The SEKO Nexa Series comprises Chemical Injection Pumps designed for heavy-duty process applications. These metering pumps feature a full motion mechanism and are available with either a packed plunger or a double hydraulic diaphragm pump head. Nexa pumps are engineered to meet and exceed the API 675 3rd Edition design standard.

Operating limits

• Pressure:
  • Plunger head: Max. Allowable Working Pressure up to 660 bar.
  • Hydraulic head: Max Allowable Working Pressure up to 450 bar.
• Flow rate: Up to 7500 l/h with a single head.
• Fluid temperature: -10 °C – 90 °C (Standard); -40 °C – 150 °C (Upon request).
• Minimum NPIP (with special solutions): As low as 0.8 barg.

Mechanical / hydraulic

• Mechanism sizes:
  • N0: 10 mm stroke length, 2 kN thrust
  • N1: 25 mm stroke length, 5 kN thrust
  • N2: 35 mm stroke length, 8 kN thrust
  • N3: 50 mm stroke length, 18 kN thrust
  • N4: 70 mm stroke length, 30 kN thrust
• Pump head types: Plunger and double hydraulic diaphragm versions.
• Casing material: Minimum grey cast iron; nodular cast iron or stainless steel are available on demand.
• Hydraulic chamber: Utilizes two different oils for mechanism lubrication and diaphragm displacement, enabling operation across wide temperature ranges.
• Motor mounting: Can be fitted horizontally (either side) or vertically.
• Flow rate adjustment: Variable stroke length, allowing adjustment from 0 to 100% of the plunger stroke length.
• Multi-head configurations: Pumps can be coupled for different tasks, injection points, or to obtain a higher smooth flow with two or three-headed pumps and manifold. Pumps can be of different sizes, flow rates, and materials, as each pump has its own reduction gear.
• Wetted parts: SS 316L, PP, PVDF, PTFE. Other exotic materials such as AISI 317L, Hastelloy © C-276, Incoloy 825, Titanium, Duplex, and Superduplex are available upon request.
• Compliance: Norsok M-501 & M-630, NACE 0175, ATEX94/9/CE, TR CU 004-010-020-012/2011, Shell DEP (various), API 675 3rd.

Electrical

• Motor options: SEKO can supply any brand and type of electrical motor (IEC, Nema, AC, DC) or electrical actuators, including their own AKTUA model.
• Electrical actuator: SEKO's in-house designed and manufactured electrical actuator is available for safe and hazardous areas (ATEX II 2 G Exd IIB + H2 T6), with single-phase multi-voltage and 50/60 Hz power supply, and 4 – 20 mA signal and feedback.
• Variable speed drives: Pumps can be supplied with variable speed drive motors (PTCs, forced ventilation, etc.) and, on demand, with relevant inverters and filters.

Features and Accessories

• Diaphragm Rupture Detector
• Manual adjustments: Smooth, easy reading, step-less, with a locking device as per API 675 requirements.
• Automatic adjustments:
  • Pneumatic adjustment for safe and hazardous areas (Air Supply 4 – 7 bar / 3 – 15 psi).
  • Pneumatic adjustment with I/P converter (Air Supply 4 – 7 bar / signal 4 – 20 mA, HART) for hazardous areas.
  • SEKO in-house designed and manufactured electrical actuator.
• Monitoring options: Local visual (standard or via pressure gauge), pressure switch (analog 4 – 20 mA, digital, HART protocol), pressure transmitter (analog 4 – 20 mA, digital, HART protocol).
• Accessories: Pulsation dampers (for suction and discharge), pressure relief valves (API 520 or 526), Y filters, back pressure valves, calibration pots.

Applications

Nexa pumps are suitable for a wide range of applications, including industrial water treatment, chemical processes, and demanding duties such as offshore upstream chemical injection. Specific industries mentioned include Oil & Gas, Petrochemical, Power Generation, Chemical, Water & Wastewater, Food & Beverages, Pharmaceutical, Paper, and Textile.

Special solutions are available for:

• Extreme chemical temperatures: Pumping chemicals at temperatures as low as -40 °C and up to 150 °C (design temperature).
• Difficult suction conditions: Handling extremely low NPIP, even as low as 0.8 barg.
• Dangerous, toxic, flammable, pyrophoric chemicals: Zero-leakage metering pumps with double diaphragm design, special valve versions, and nitrogen flushing systems to prevent leakage and ensure safety.
• Low ambient temperatures: Reliable operation in ambient temperatures as low as -40 °C, achieved through features like nodular cast iron/SS casing hydraulic chambers, low pour point hydraulic oils, special hydraulic inner chamber component design, special painting, and oil heaters.

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Disclaimer: This summary is based on extracted text and may not include all figures, footnotes, or the latest revisions from the official OEM PDF datasheet. Contractual data must always match the specific OEM PDF revision used on the project.

Official datasheet (PDF)

Lenntech datasheet mirror