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Hygienic twin-screw pumps: supersession and spare parts availability

The SLH-5G supersedes both the SLH-4G and the SLH-4U. No end-of-support date has been published.

UPDATED 13 JULY 2026EVERY FIGURE SOURCED WHERE NOTHING IS PUBLISHED, WE SAY SO
The short answer

The SLH-5G supersedes both the SLH-4G and the SLH-4U. Spare parts for the superseded generation remain available at present.

No end-of-support date has been published, and no mechanical seal replacement interval is published for the SLH-4G. Both questions are with the manufacturer's channel.

01Equipment

ItemDetail
PumpSLH 180 hygienic twin-screw
PrincipleNo metal-to-metal contact between the screws
SLH-4G capabilityTo approx. 177 °C; differential pressure to 362 psi; pumps CIP solution directly
StatusSuperseded by the SLH-5G, which replaces both the 4G and the 4U

Source: manufacturer product literature, twin-screw hygienic pump range.

The pump handles product and then handles the CIP solution that cleans it without a changeover, which is normally the reason it is specified. Supersession does not affect its performance in service.

02What supersession means in practice

Parts availability after supersession typically follows a sequence. Each stage is manageable if the plant knows which stage it has reached.

1
Parts remain available on normal lead times. The new generation is launched.
2
Stock is no longer held. Lead times lengthen and parts move to made-to-order in batches.
3
Order-only, with a minimum order quantity. Pricing changes.
4
End of support.

The position of a specific installation in this sequence is established by asking the manufacturer directly and recording the answer in writing.

03The mechanical seal

The mechanical seal on an SLH twin-screw is a four-figure euro item. No replacement interval is published for it.

Consequence of an unpublished interval

Where a part has no published interval, it receives no planned replacement. In practice the seal runs to failure on a hygienic duty, on a pump whose generation is superseded, in a plant where line downtime exceeds the value of the pump.

04Recommended actions

1
Record the serial numbers. The manufacturer establishes nothing about a specific pump without its serial number. The serial is on the nameplate, and a photograph of the nameplate is sufficient.
2
Obtain the availability position in writing. The relevant questions are whether an end-of-support date has been set, and the current lead time for 4G spares. Both have been submitted.
3
Hold one seal set in stock. The holding cost is the cost of capital. The alternative is airfreight, expediting and downtime.

The contents of a full annual wear kit for the pump, and whether an H1 food-grade lubricant is specified for the gearbox and bearings in hygienic service, form part of the same enquiry.

The drawing

Two screws that never touch — and one face that does

The screws are perfect. The seal face is the part with no published interval.

PROCESS PUMPS
FIGSCHEMATIC · THE SHAPE IS THE POINT · THE NUMBERS ARE YOURS
Every figure on this page — and where it comes from
SOURCED
FigureValueSource
SLH-4G temperatureto approx. 177 °CManufacturer product literature
SLH-4G differential pressureto 362 psiManufacturer product literature
SupersessionSLH-5G replaces both SLH-4G and SLH-4UManufacturer product literature
Mechanical seal intervalNOT PUBLISHEDNo manufacturer figure located.
End-of-support date, 4G sparesNOT PUBLISHEDEnquiry submitted; awaiting response.
i If you find an error on this page, tell us — and we will correct it publicly.

!What is not published

No end-of-support date for SLH-4G spare parts has been published, and none has been located in any manufacturer document.

No mechanical seal replacement interval is published for the SLH-4G. Both questions are with the manufacturer's channel. Answers will be published on this page with the date they were given and the party who gave them.

?Questions we are asked

Is the SLH-4G obsolete?

It is superseded. The SLH-5G now replaces both the SLH-4G and the SLH-4U. Parts remain available, but no end-of-support date has been published.

How often should the mechanical seal on an SLH 180 be replaced?

No interval is published. In practice the seal is run to failure. Given the cost of the part and the duty, holding one seal set in stock is the normal precaution.

What can the SLH-4G handle?

Approximately 177 °C and a differential pressure to 362 psi, with no metal-to-metal contact between the screws. It pumps CIP solution directly.

The failure guide

The whole of this, in Arabic,
on your maintenance engineer's desk.

Bilingual Arabic/English. Symptom index, published intervals, the elastomer question, and what one pump consumes in a year. Printable. Free. Ask and we will send it.