Replacement for John Crane Type 609 Metal Bellows Seal

Type 609 Replacement Overview

This Type 609 metal bellows mechanical seal is supplied as a replacement seal for high temperature pump service where elastomer secondary seals are not suitable. The welded metal bellows design provides spring force and torque transmission without a dynamic O-ring on the shaft, helping the seal operate reliably in hot oil, refinery, petrochemical and chemical transfer duties. Fluid Tech Service can supply Type 609 replacement seals in standard metric sizes from 24 mm to 100 mm, with seal face and metal parts selected according to the pumped medium, temperature, pressure and shaft speed.

Key Features

• Replacement design for John Crane Type 609 metal bellows mechanical seals.
• Suitable for high temperature and low temperature service from -75 C to 400 C.
• Flexible graphite secondary sealing option for applications where rubber O-rings cannot withstand the operating temperature.
• Balanced welded metal bellows structure for stable face loading and reduced leakage risk.
• Available with carbon, silicon carbide, sintered silicon carbide or tungsten carbide seal faces.
• Metal bellows and hardware available in 304, 316, Hastelloy C or Inconel alloy depending on corrosion requirements.

Operating Limits

Item	Value
Temperature	-75 C to 400 C
Pressure	Up to 25 bar
Speed	Up to 20 m/s
Standard shaft sizes	24 mm to 100 mm

Material Options

Part	Available Options
Rotary and stationary faces	Carbon graphite, silicon carbide, sintered silicon carbide, tungsten carbide
Secondary seal	Flexible graphite or FFKM, selected by temperature and medium
Bellows and metal parts	304 stainless steel, 316 stainless steel, Hastelloy C, Inconel alloy

Typical Applications

Type 609 metal bellows seals are commonly used on high temperature process pumps and transfer pumps in petroleum refining, petrochemical plants, chemical production and hot oil circulation systems. They are a strong option for clean or lightly contaminated fluids where temperature, corrosion resistance and dimensional stability are more important than low-cost elastomer sealing.

• Hot oil transfer pumps
• Refinery process pumps
• Petrochemical circulation pumps
• Chemical industry high temperature pumps
• ANSI and DIN process pump applications

How to Select the Right Type 609 Replacement Seal

To confirm the correct replacement, please provide the shaft size, seal chamber dimensions, working temperature, pressure, pump speed, pumped medium and any drawing or old seal photos. For clean high temperature oil service, carbon versus silicon carbide is often selected for stable running. For abrasive, crystallizing or particle-containing media, confirm the face combination together with the complete seal arrangement and support system; a harder face pair alone does not establish suitability.

Type 609 Replacement: Check the Assembly, Not Just the Shaft Size

A 609 designation is a starting point for a replacement enquiry. Before ordering, compare the proposed seal with the complete installed assembly, including the stationary seat and its mounting details. A matching shaft diameter alone does not confirm that the parts will fit the pump.

Build a dimension record from the drawing and the removed seal

• Shaft or sleeve: record the diameter at the seal location and identify whether the seal mounts directly on the shaft or on a sleeve.
• Axial space: provide the specified working length and available chamber depth. Label a loose seal measurement as free length; do not substitute it for the installed working length.
• Stationary seat: include the seat outside diameter, thickness, housing bore and retention or anti-rotation details shown on the assembly drawing.
• Replacement scope: state whether the enquiry covers the rotating head, a head and seat set, or a complete assembly. Include photographs of both mating faces and the mounting arrangement.

If an old component is worn or damaged, mark that measurement as approximate. Use the pump drawing or an approved seal drawing to resolve the uncertain dimension before manufacture.

Describe what happens during start-up and shutdown

For a hot-oil duty, send normal operating conditions together with cold start-up conditions, maximum expected temperature and seal-chamber pressure. Also identify any flushing, cooling or quench arrangement. These details help distinguish a dimensional replacement from a change that requires further application review. For fluids that leave deposits or contain solids, describe the deposits found on the removed seal and provide photographs. Selecting a harder face pair alone does not establish suitability: the complete seal arrangement and the conditions around the faces still need to be reviewed.

Read the operating limits as selection boundaries

The temperature, pressure and speed values listed on this page are separate reference limits, not a promise that every material combination can operate at all three maxima simultaneously. Request confirmation for the selected faces, secondary seals and metal parts at your actual duty. Ratings published for an original manufacturer’s product should not be assumed to apply to an aftermarket replacement.

A useful first enquiry

Send a single enquiry with: pump model; existing seal identification; drawing or dimension record; required replacement parts; fluid and concentration; normal and maximum temperature; seal-chamber pressure; shaft speed in rpm; support-system details; and quantity. If the old seal failed, add when leakage began and whether it occurred during normal running, start-up or shutdown. Send your Type 609 replacement enquiry or browse the metal bellows seal range.