ESKO Offers a full range of maintenance support. Keeping spare parts on hand can help minimize downtime.

Replacement parts, complete rebuild kits, and o-ring kits are available for all ESKO flow meters. Proximity alarms, floor stands, and constant flow regulators can be fitted upon installation or added later.

Factory Refurbishing

ESKO also offers budget-friendly factory refurbishing to complement in-house maintenance programs. Refurbishing includes a thorough cleaning and check, replacement of worn parts as necessary, and full factory re-testing.

O-ring kits

O-rings available in Nitrile, Viton or EPDM
O-ring kit for EMO multi-tube flow meter
O-rings available in bulk


Esko offers O-ring kits designed specifically for maintenance of ESKO flow meters. The kits include all the replacement O-rings for complete cleaning and rebuild, with installation and placement information. O-rings in various sizes and materials are also available in bulk.

Over time, O-rings can harden and eventually crack. Typically, O-rings should be replaced every few years, or more often in critical applications or harsh environments. O-rings should always be replaced when a flow meter is disassembled for service.

Detailed Specifications

Prior to installation, ensure that the O-rings are the right material. Standard oil applications normally use Nitrile rubber O-rings. For synthetic oils, Viton and sometimes EPDM is recommended.

Refer to the assembly breakout diagrams to ensure that the correct size O-rings are placed in the correct positions as each flow meter will have several O-rings of varying sizes.

Replacement flow tubes

Model EHC tubes in Grilamid or PSU
Model ECC tubes in Grilamid or PSU
Model ESF Borosilicate tube


Over time, flow tubes can become discolored or be accidentally damaged during operation or maintenance. ESKO offers a full range of replacement parts including flow tubes and other components for maintenance of all ESKO products. Full factory refurbishing is also available.

Detailed Specifications

It is important to choose the right flow tube material for each application. Flow tubes are application specific. As a quick overview: Acrylic flow tubes are common for standard applications, Trogamid and Polysulphone (PSU) flow tubes are freeze-resistant, Borosilicate glass offers chemical resistance and Grilamid flow tubes are recommended for higher temperature applications.


SS float with guide rod in Model EH meter
Float option in Model EM
There are 100’s of float designs. Some can be installed as shown or inverted.


Floats may become lost or damaged during maintenance. Having spare parts on hand can help keep processes running smoothly. Floats are not interchangeable.

Detailed Specifications

Float shapes and materials vary depending on flow tube design and taper, flow media, temperature range and other factors. Depending on the model design, available float materials include stainless steel, tungsten carbide, glass, sapphire, Teflon or POM, guided by application specific factors.

Flow control valves

Flow control valve
ESKO Back Pressurizing Valve for Model ESF Seal Water Monitor
ESF Back Pressure Valve
ESKO Back Pressurizing Valve for Model EMI Seal Water Flow Meter
EMI Back Pressure Valve


Many ESKO flow meter models offer flow control valve options to adjust the flow to process requirements. For example, ESKO EM style flow meters can be customized to include a flow control valve on the outlet (Model EMO) or on the inlet (Model EMI).

Pressurizing valves are common in seal water applications. Installing a back pressurizing valve on a seal water monitor provides control of seal water pressure and prevents undesired backflow which can reduce seal life.

Detailed Specifications

Control valves are usually constructed from durable materials including stainless steel, Teflon and CPVC and typically do not need to be replaced unless they are damaged due to external forces. If meters with control valves are serviced or dismantled for cleaning, O-rings on the control valves should be replaced.

Optimal seal life can be achieved by following seal manufacturers’ specifications for operating conditions to ensure both proper flow and proper pressure. ESKO modular designs allow for pressurizing valves to be installed subsequent to initial installation of a flow monitor.

Pressure gauges

Pressure gauge on Model ESF seal water monitor
WIKA pressure gauge with or without red set pointer
Pressure gauge on Model EMI seal water meter


The versatile design of ESKO flow meters allows for a pressure gauge to be installed after a flow meter has been installed. In seal water installations, for example, flow meters provide information about flow into the seal but adding a pressure gauge indicates seal water pressure, which is critical to the longevity of mechanical seals. Pressure gauges can also be added to various other variable area flow meters.

Detailed Specifications

Gauges are available with or without a red set pointer and can be used to indicate whether there is sufficient pressure into a process. In seal water monitoring real-time visual monitoring can prevent excess water finding its way into the process, which can be costly to remove.

Proximity alarm sensors

IFM inductive proximity sensor fits on many ESKO meters
Alarm sensor mounted on EM side plate
Alarm sensor mounted on back of EDF seal water monitor


An alarm sensor mounted directly onto a flow meter detects the proximity of a metal float inside the flow tube to provide low flow or high flow signals as required.  When a float drops below the set point chosen by the operator, an alarm is generated.  Maintaining appropriate flows can extend the life of mechanical seals, pumps, and bearings. 

Detailed Specifications

To provide precise monitoring information, alarm sensors can be fitted at any time onto most ESKO flow meters. Depending on the flow meter type, back, side or bottom installation is possible. Due to their modular design, ESKO flow meters also have multiple alarm capability for detecting no flow, low flow, or dual (high/low) alarms.

Constant flow regulators

Model EFR3 designed for Model ELF flow meters
Model EFR14 designed for Model EM flow meters
Model EFR3 paired with ELF flow meter


Supply pressure, back pressure and pressure fluctuations can all cause unexpected changes in process flow. Adding a constant flow regulator to in-line flow meters can reliably stabilize flow by providing a constant flow of liquids or gases, regardless of supply pressure variations. Read more about how constant flow regulators work.

Detailed Specifications

Where small to medium flow meters are already installed, a constant flow regulator may be an easy addition, but they can also be installed without a flow meter/monitor.

The most common applications of flow meters paired with constant flow regulators in pulp and paper processing include seal water/cooling water, tank level and density measurement, orifice plate flow measurement, solvent/additive inflows, batching liquids, moisture control and air purging.

Mounting brackets

Mounting bracket on EMI
Mounting plate on ESF
Mounting bracket on EMI with pressure gauge option


Mounting a meter in an optimal location is possible with standard design durable mounting plates that protrude on the back or side of many ESKO flow metering products.  Due to their robust design, ESKO flow meters are typically mounted in process areas. 

Detailed Specifications

Mounting plates are also available in custom variations including bent plates to allow for wall mounting.

Floor stands

Model EDF seal water monitor on stand
Model EDF seal water monitor with mounting plate
Model ESF mounting plate for stand


Where standard bracket mounting is not feasible, floor stands are an option. Typically used in seal water monitoring applications, these stainless steel stands mean that monitors can be installed in optimal locations for easy visual access.

Detailed Specifications

Floor stands are 30” tall and shipped in two pieces for easy shipping and assembly on site. The mounting plate has bolt holes for permanent floor installation.


Model ESF straight tube fittings
Model ESF NPT male threads
Model ESF compression fittings


ESKO products are designed for easy installation with a variety of connection options to integrate with your process. North American NPT process connections in various sizes are most common on all ESKO flow meters. Contact us about installation options for specific applications.

Detailed Specifications

The popular Model ESF and EDF seal water monitors feature a number of connection options including hose barbs, straight tubes, compression fittings, and male/female versions of the North American standard NPT fittings.

Learn about Product Maintenance

How to Estimate Flow Rate

Practical guidance on estimating liquid and gas flow rates.

Product guidance >>

Installation, Cleaning and Maintenance

The basics: installation tips, cleaning flow tubes, o-ring life span, replacement and reassembly.

Basic product info here >>