Danfoss 060-315766 KPI 35 Pressure Switch -0.2 to 8 bar

KPI 35 pressure switch for liquids and gases in an IP55 housing

The 060-315766 is a Danfoss KPI 35. In the KP/KPI data sheet the KPI letters mark the types that suit liquid as well as gaseous media, which is why this model is used on water circuits, oil lines and coolant loops where a KP switch would be ruled out. It switches an SPDT contact from -0.2 to 8 bar with a tight 0.4 to 1.5 bar differential, so it can hold a narrow pressure band for example around a circulating pump or a small booster set.

The IP55 enclosure is the main distinction from the IP30 KP 35 to KP 37 switches: it tolerates dust and water jets, which suits pump rooms and machine bases. Reset is automatic and the connection is a G 1/4 male thread.

Technical specifications

Low-pressure control and dry-run protection use cases

With a lower limit of -0.2 bar the switch can detect loss of suction pressure and stop a pump before it runs dry. Set the cut-out slightly above the minimum suction pressure the pump requires and keep the differential at the narrow end for protection duty. For pressure control of a small circuit, a cut-in at 3.0 bar with a 0.6 bar differential gives a cut-out at 2.4 bar.

The maximum working pressure equals the test pressure at 18 bar, so there is little margin above the 8 bar range limit for hydraulic shock. If the circuit can see water hammer, fit a pulsation damper or a needle valve in the impulse line, and pick a higher-rated type where peaks may exceed 18 bar.

Fitting and verification notes

Install the switch vertically or according to the installation guide for KPI 34, KPI 35, KPI 36 and KPI 38, keep the impulse line short and free of trapped air and use the sealing washer on the G 1/4 thread. Verify the contact function with the manual trip lever before the system is pressurised.

Before ordering, confirm that the wetted materials are compatible with your medium, that the required setting fits inside -0.2 to 8 bar and which contact material you need, since gold-plated and manual-reset versions are separate code numbers. Seven Star LLC is an independent supplier in Muscat; send the code and the duty and we will respond with availability.

A good enquiry for 060-315766 lists the code, the quantity, the site, the required documents and any approval certificates your inspector will ask for. Sending these together, rather than one by one, shortens the exchange and reduces the chance of a mismatch at delivery.

Selection checks for the KPI 35

Before the code number is fixed, write down the medium, the normal operating pressure, the lowest and highest pressure the circuit can reach, and whether the switch is there for control or for protection. A control duty usually wants the setting near the middle of the regulating range so that adjustment is comfortable in both directions; a protection duty wants a setting that leaves a clear gap between the normal operating point and the trip point, so that ordinary fluctuations do not cause nuisance stops. Check that the chosen cut-in and cut-out values, including the differential, sit inside the published range, and compare the contact rating with the actual load: a contactor coil, a relay input or a PLC input each loads the contact differently. Where an inspector or classification society is involved, confirm that the approvals already listed for this code number are the ones the project requires.

Setting and commissioning on site

Set the switch against a calibrated reference gauge fitted close to the impulse connection, not against a panel gauge some distance away. Raise and lower the pressure slowly through the set points several times and note the values at which the contact changes over, then adjust until the readings repeat. Record the final cut-in and cut-out values, the date and the reference gauge used on the commissioning sheet, and fix a label near the switch so maintenance staff know the intended setting. Check the wiring for the correct use of the SPDT contact, since a protection circuit is normally wired so that a broken wire or loss of supply stops the equipment rather than leaving it running. Finally, confirm the trip in practice by simulating the low or high condition and observing that the pump or machine responds as designed.

Routine maintenance

Pressure switches on pumps and coolant loops are easy to forget once a plant is running. Include the KPI 35 in the planned maintenance schedule: verify the set points against a reference gauge at a fixed interval, look for leaks at the G 1/4 connection, check that cable entries are still sealed and that the enclosure cover is fitted correctly to keep the IP55 protection. If the switch has been exposed to repeated pressure peaks or the readings drift from the recorded settings, replace it rather than continuing to readjust.

Operating conditions in Oman and the GCC

Pump rooms, rooftop plant and skid-mounted packages in the Gulf combine high ambient heat, airborne dust and, near the coast, salty humid air. Mount the switch where it is not in direct sun or beside hot pipework, and compare the conditions at the mounting point with the limits in the Danfoss data sheet. Keep the impulse line protected from mechanical damage and, for water service, think about where condensation or stagnant water may collect. Dust settling on the enclosure is not a problem in itself, but cable glands and the cover must stay closed and intact so that dust and wash-down water stay outside.

Documents and quotation

We attach the Danfoss KP and KPI pressure switch data sheet AI557543881535, which gives the ordering table, dimensions and wiring. Related controls are in our pressure instrumentation category. To request a price, quote 060-315766.