ERECTA SWITCH® by Compac Engineering
Series 5 · ERECTA SWITCH®

5-20-LF — Low Flow Switch Set

Ultra-low flow detection set. Spring in: 0.042 GPM. Spring removed + vertical mount: 0.008 GPM. Angle body with low-flow trim. Available in Polypropylene, Acetal, and Kynar PVDF.

Choose Your 5-20-LF Material

The 5-20-LF is available in three wetted materials. Polypropylene for water-based and mild chemical service. Acetal for solvents, fuels, and hydrocarbons. Kynar PVDF for aggressive acids, halogens, and ultra-high-purity applications.

Specifications

Common specifications across all 5-20-LF material variants.

SpecificationValue
Series5-20-LF
BodyAngle body (5-20)
Setpoint (spring in)0.042 GPM
Setpoint (spring removed, vertical)0.008 GPM
SwitchHermetically sealed reed | SPST N.O.
Contact Rating70 VA / 50W | 0.5A AC / 0.7A DC
Ports3× 9/16-18 UNF
Lead Wire24 in (600 mm)
ComplianceRoHS
Frequently Asked Questions

Common Questions About This Product

What are the typical applications for the 5-20-LF?

The 5-20-LF is used for pump start/stop control, high-level overflow protection, low-level dry-run protection, and tank or reservoir level alarms in OEM equipment. The modular ERECTA SWITCH system is built into laundry, HVAC, water-treatment, hydraulic, and chemical-handling machinery.

What liquid chemistries is the 5-20-LF compatible with?

Choose the material to match the media: Polypropylene (PP) for general aqueous, acids, and bases; Acetal (AC/Delrin) for solvents, fuels, and hydrocarbons; Kynar PVDF (KR) for aggressive or harsh chemicals. Every ERECTA SWITCH model is offered in all three materials.

How do I wire the 5-20-LF to a pump or alarm?

The 5-20-LF uses a magnetic reed switch wired in series with your relay or controller. Contact rating is 70 VA / 50 W resistive (UL File E70063). The switch ships with lead wires — connect directly to your control circuit.

Does the 5-20-LF need calibration?

No. The 5-20-LF is a mechanical float actuating a sealed reed switch — there is nothing to calibrate or power. This is a reliability advantage over electronic sensors that can drift over time.

How do I maintain the 5-20-LF, and what if it stops working?

Inspect that the float moves freely (check for debris or scaling), then test reed continuity with a multimeter. Because ERECTA SWITCH is modular, you replace only the individual component — switch, float, connector, or fitting — instead of the whole assembly.

What pressure and temperature can the 5-20-LF handle?

Series 10 level switches are rated to 100 PSI; Series 5 flow switches to 200 PSI. Operating temperature depends on the housing material — Polypropylene, Acetal, and Kynar PVDF each have different thermal limits. Contact Compac engineering for your specific conditions.

Need Help Selecting a Material?

Our engineering team can verify chemical compatibility with your application before you order.