De Nora NXT3000 Series

Questions and Answers

D
David WaltersAug 5, 2025
What to do if the flowmeter ball bounces in De Nora Measuring Instruments?
- A
  Andrew PowellAug 5, 2025
  If the flowmeter ball bounces or the maximum gas feed rate cannot be achieved during normal operation of your De Nora Measuring Instruments, it could be due to several reasons. The vacuum regulator inlet filter screen might be dirty, requiring replacement of the gas inlet filter. Alternatively, the rate valve or flowmeter could be dirty and need cleaning, refer to the Service section for instructions. Another potential cause is fluctuating ejector water supply pressure leading to insufficient ejector vacuum; in this case, check and correct the water supply pressure as needed.
Z
Zoe LeeAug 13, 2025
How to fix vacuum leaks in De Nora Measuring Instruments?
- B
  brenda49Aug 13, 2025
  If you're experiencing vacuum leaks in your De Nora Measuring Instruments, it might be due to worn rate valve o-rings, which would need replacement. Another cause could be a loose tubing connector, which needs tightening. Finally, check for cracks in the tubing; if present, the tubing must be replaced.
J
jonescharlesAug 19, 2025
Why is the gas feed rate not achieved at start-up in De Nora Measuring Instruments?
- J
  Juan JonesAug 19, 2025
  If the required gas feed rate is not achieved at start-up of your De Nora Measuring Instruments, it could be due to: * Leakage at vacuum line connections, vacuum regulator, and/or inlet to ejector - inspect each connection and remake as necessary. * Crimped vacuum lines - replace vacuum tubing and arrange lines to eliminate the crimp.
B
Barbara JoyceAug 27, 2025
What to do if there is a flooded metering tube in De Nora Measuring Instruments?
- L
  Lindsey CaldwellAug 27, 2025
  If you notice a flooded metering tube in your De Nora Measuring Instruments, it is likely due to dirt on the ejector check valve seat or a worn seat. Clean or replace the ejector check valve seat.

Summary

Introduction to Series NXT3000 Meter Assembly

General Meter Assembly Information

Overview of the meter assembly's design, mounting, and proper use for optimal operation.

Warranty and Service Policy

Details on the warranty status and service policy for the Capital Controls equipment.

Series NXT3000 Meter Assembly Specifications

Technical data including meter tube scale length and recommended tubing connection sizes.

Configuration of Multiple Meter Assemblies

Explains how to connect up to five individual meter assemblies into one unit for multi-point feeds.

Operation of Series NXT3000 Meter Assembly

General Meter Assembly Operation

Describes the variable area type meter, rate valve function, and capacity indications.

Installation Procedures

Step-by-step guidance for installing the meter assembly in upright and level positions.

Maintenance and Service Recommendations

The document describes the De Nora Series NXT3000 Meter Assembly, a component designed to complement Capital Controls' Series NXT3000 vacuum regulators in gas feed systems. This meter assembly provides visual indication and control of gas flow rates.

Function Description:

The Series NXT3000 Meter Assembly is a variable area type meter that visually indicates the gas flow rate. It is designed to work in conjunction with Capital Controls' Series NXT3000 vacuum regulators. The gas flow rate is set by an internally mounted manual rate valve. For systems with an automatic Chloromatic rate valve assembly, the rate valve knob on the meter assembly's outlet fitting will be glued in place, indicating that it is not intended for manual adjustment in such configurations. The meter assembly can be mounted directly on the vacuum regulator or remotely on a wall. It can also be ganged with up to five individual meter assemblies to create a multipoint feed system for multiple feed points.

Important Technical Specifications:

Capacity Range: 1-500 PPD (pounds per day) or 10 kg/h (kilograms per hour) maximum.
Meter Tube Scale Length: 4 inches.
Gas Compatibility:
- Chlorine, Sulfur Dioxide, Carbon Dioxide:
  - 1, 3, 10, 25, 50, 100 PPD (20, 60, 200, 500 g/h, 1, 2 kg/h) - Minimum Inlet & Outlet Tubing Connection sizes: 3/8"
  - 200 PPD (4 kg/h) - Minimum Inlet & Outlet Tubing Connection sizes: 1/2"
  - 300, 500 PPD (5, 10 kg/h) - Minimum Inlet & Outlet Tubing Connection sizes: 5/8"
  - Note: Carbon dioxide service uses a chlorine tube with a factor x 0.75.
- Ammonia:
  - 5, 10, 25, 50, 100 PPD (30, 100, 250, 500 g/h, 1 kg/h) - Minimum Inlet & Outlet Tubing Connection sizes: 3/8"
  - 100 PPD (2 kg/h) - Minimum Inlet & Outlet Tubing Connection sizes: 1/2"
  - 250 PPD (5, 10 kg/h) - Minimum Inlet & Outlet Tubing Connection sizes: 5/8"
Tubing Fittings: Each meter assembly is furnished with 3/8", 1/2", and 5/8" tubing fittings. The recommended minimum tubing sizes vary based on capacity, and larger sizes may be required for long vacuum line runs.
Associated Components:
- Vacuum regulator: 100.6701
- Ejector: 122.6060
- Meter Assembly Dimensions: 100D1027
Mounting Hole Locations (for 1/4" [6] Dia Bolts):
- 1 Assembly: "A" Dim 2-1/16 [52], "B" Dim 2-11/16 [68]
- 2 Assemblies: "A" Dim 4-1/8 [105], "B" Dim 4-3/4 [121]
- 3 Assemblies: "A" Dim 6-3/16 [157], "B" Dim 6-13/16 [173]
- 4 Assemblies: "A" Dim 8-1/4 [210], "B" Dim 8-7/8 [225]
- 5 Assemblies: "A" Dim 10-5/16 [262], "B" Dim 10-15/16 [278]
- Note: "A" and "B" dimensions refer to specific mounting plate measurements.

Usage Features:

Installation: The meter assembly must be installed in an upright and level position for proper function. It comes with o-ring seals, mounting feet, and tubing fittings for direct mounting on a vacuum regulator or a wall.
- Integral Mounting (on Vacuum Regulator): The seal O-ring is seated in the outer counterbore of the gas outlet connection of the vacuum regulator, and the flowmeter-rate valve assembly is mounted on the side of the regulator. Mounting plates and adaptor fittings (for wall mounting) are not needed in this case.
- Wall Mounting: Mounting plates are installed on the rear of the meter assembly, and adaptor fitting(s) are installed in the gas outlet connection of the vacuum regulator(s). If only one assembly is used, an adaptor fitting is installed in its gas inlet connection.
- Multiple Meter Assemblies: Up to five individual meter assemblies can be ganged together to form a multipoint unit. When ganged, the proper tubing size is determined by adding the capacities of all meters in the final assembly.
Tubing: Black polyethylene tubing is typically used for the vacuum line. Kinking should be avoided, and tubing connectors, tees, or elbows can be used to ensure a direct run. Sufficient tubing length should be provided to allow movement of the vacuum regulator for servicing or cylinder changes. Tubing connector nuts should be tightened HAND TIGHT. Routing vacuum tubing through unventilated conduit is discouraged due to potential gas diffusion.
Operation: The rate valve, located at the meter outlet (top), is sized to match the meter capacity. The calibrated scale on the flowmeter tube provides direct readings in pounds per day (lb/d), grams per hour (g/h), or kilograms per hour (kg/h).
Start-up: After system leak testing and operation, the rate valve is adjusted to the desired gas flow rate. The flow rate is read at the center of the ball on the flowmeter scale.
Safety Note: The rate valve on the remote meter panel should NEVER be used to shut off the gas supply, as this will damage the valve. To shut off the gas, the gas container valve must be closed.
Warranty: The Capital Controls equipment warranty and service policy (005.9001) is void if the Series NXT3000 Meter Assembly is misapplied.

Maintenance Features:

Recommended Inspection: The Gas Dispensing System should be inspected and serviced regularly, at least once per year. Depending on usage, operating procedures, gas flow rate, and gas quality, the maintenance period may need to be shortened.
Preventative Maintenance Kits: These kits are available from the factory and include all necessary parts and detailed instructions for complete maintenance. All resilient parts (O-rings, gaskets) must be replaced during reassembly to ensure safe and trouble-free operation. Failure to replace these parts can result in bodily injury.
Preventative Maintenance Kit for chlorine and sulfur dioxide: P/N 614S096U01.
Troubleshooting Chart: The manual includes a troubleshooting chart to address common issues:
- Required gas feed rate not achieved: Possible causes include insufficient ejector vacuum, leakage at vacuum line connections, crimped vacuum lines, or excessive vacuum line length. Corrective actions involve referring to Trouble 2, inspecting/remaking connections, replacing/arranging tubing, or referring to Bulletin 121.3003.
- Flowmeter ball bounces or maximum gas feed rate not achieved: Possible causes include a dirty vacuum regulator inlet filter screen, dirty rate valve, dirty flowmeter, or fluctuating ejector water supply pressure. Corrective actions involve replacing the gas inlet filter, cleaning the rate valve, cleaning the flowmeter, or checking/correcting water supply pressure.
- Flooded metering tube: Possible cause is dirt on or a worn ejector check valve seat. Corrective action involves cleaning or replacing the ejector check valve seat (refer to Ejector instruction manuals 122.6006, 122.6010, 122.6015, or 122.6060).
- Vacuum leaks: Possible causes include worn rate valve o-rings, loose tubing connectors, or cracks in tubing. Corrective actions involve replacing o-rings, tightening tubing connectors, or replacing tubing.
Component Breakdown: For detailed component breakdown, refer to parts list 100.7602.