Ashcroft SL17 Submersible Pressure Transmitter, 316L

Ashcroft SL17 submersible pressure transmitter for well, tank and sump level

The Ashcroft SL17 is a slim, fully 316L stainless steel submersible pressure transmitter that is lowered into a well, tank or sump to measure liquid level from the hydrostatic pressure of the column above it. It gives a 2-wire 4-20 mA signal, a polyurethane vented cable of the length you order and an IP68 / NEMA 6P housing. The small outside diameter lets it fit narrow-bore applications such as boreholes. Seven Star LLC supplies the SL17 in Oman and the GCC as an independent supplier in Muscat, and this page explains the ordering code, specifications and practical points for water level duty.

How the SL17 measures level

A liquid column exerts a pressure proportional to its height and density. The SL17 uses piezo-resistive technology (PRT) in its sensor to convert that pressure into an electrical signal, and the electronics scale it to a 4-20 mA output. The sensor is a gauge-pressure type, so the reference side must be vented to atmosphere through the vent tube in the cable. The data sheet states the ranges are based on the cable being vented to a clean, dry, non-corrosive atmosphere or on proper use of a termination desiccant box, because moisture in the vent tube can cause errors. Units of measure can be psi, bar, feet or metres of water, or customer-defined units.

Technical specifications of the SL17

Reading the SL17 order code

The data sheet shows the example SL17 3 SNC T 42 010 F P 10# XC4: the SL17 transmitter with accuracy code 3 (±0.25 percent of span), a standard nose cone (SNC), a threaded joint (T), 4-20 mA output (42), a 10 ft cable (010 and F for feet), polyurethane cable (P), a 0-10 psi range (10#) and the traceable calibration certificate option (XC4). Accuracy code 5 (±0.5 percent) applies to the 1.5 psi range only. The nose fitting can also be the weighted P5C version, which helps the transmitter hang straight in a moving liquid. The joint can be threaded or welded. Standard cable lengths run from 1 to 700, in feet or metres, and custom lengths are possible, for example 035 for 35 ft.

Selection and ordering checklist for the SL17

• Level span: convert the depth of liquid to pressure (1 m of water is about 0.1 bar) and choose a range with margin.
• Cable length to the junction box or termination, plus extra for installation depth.
• Weighted or standard nose cone, depending on current and turbulence.
• Liquid compatibility with 316L stainless steel and polyurethane cable.
• Liquid temperature between -10 and 40 °C and not frozen.
• Vent: use the termination desiccant box where humidity is high.
• Calibration certificate and any custom unit of measure.

Installation, protection and maintenance

Lower the transmitter on its cable, support the cable at the surface so the weight is not carried by the connection, and keep the vent end dry. In boreholes with long cables, a surge protector at the cable head helps protect the electronics from induced voltages, and the loop should be wired with a shielded pair. Check the zero with the transmitter out of the liquid and vented. Keep the nose cone clear of sludge, because blocked ports give a false reading, and withdraw the transmitter periodically for inspection in dirty water. Do not use it in frozen liquid, and take the 2:1 turndown limit into account when re-ranging.

Typical applications in Oman and the GCC

The manufacturer lists well monitoring, pump protection, tank level monitoring, municipal and industrial water, groundwater level, wastewater and specialised OEM equipment. In Oman and the GCC, a vented submersible transmitter fits borehole and falaj monitoring, groundwater observation wells, water storage tanks, wet wells and sumps at pumping stations and cooling water pits. Groundwater supplies are important and monitoring drawdown protects pumps from running dry.

Information to send with an RFQ for the SL17

• Level span and pressure range, units of measure
• Cable length and type, nose cone choice
• Liquid, temperature and installation depth
• Calibration certificate and accessories
• Quantity and delivery site

Site conditions in Oman for the SL17

Field instruments in Oman are exposed to strong sun, high ambient temperature, wind-blown dust and, on coastal plants, salt in the air. When you specify the SL17, check the ambient and process temperature limits, the enclosure rating and the wetted and housing materials against the actual installation point, and consider sunshades for transmitters mounted in direct sunlight. Cable entries should be sealed with suitable glands so that dust and moisture cannot enter the housing.

Calibration and verification planning matters as much as selection. Record the range, configuration and tag data of each SL17 at commissioning, define a check interval that suits the criticality of the loop, and keep the certificates with the plant documentation so that audits and shutdown work can proceed without delay.

Documents and quotation

The Ashcroft SL17 data sheet is attached on this page. It includes the range table and the full order code structure.

Send the level span and cable length and Seven Star LLC will confirm availability and prepare a quotation.