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Rubber Bellow Mechanical Seal Manufacturer in Mumbai, India
Need a seal that keeps sealing even when the shaft isn't perfectly aligned — without a dynamic O-ring that can hang up, wear the sleeve, or clog on solids?
Ashish Seals India manufactures elastomeric rubber bellow mechanical seals in Mumbai in helical coil spring and conical spring constructions, standard design, single mechanical seal, outside mounted and independent of direction of rotation — available with or without a bearing, for shaft diameters from 25 mm to 80 mm, up to 12 bar and 180°C (product range BS12C). We've been building mechanical seals in Mumbai since 2005.
A rubber bellow works differently from a conventional O-ring seal: the elastomer bellow itself slides along the shaft or sleeve to take up axial movement and shaft runout, instead of a dynamic O-ring doing that job. There's no secondary seal hanging up or fretting the sleeve, and because torque isn't transmitted through the elastomer on the helical version, the seal keeps working regardless of rotation direction. That's what makes this construction the standard choice for water, sewage and effluent duties where a conventional seal wears out fast.
Types of Rubber Bellow Mechanical Seals
Elastomeric Rubber Bellow Helical Coil Spring Mechanical Seals
Built around an open-coil helical spring wound at a constant diameter, resisting the compressive force applied axially. Torque is transmitted through the spring and spring holder
View Helical Coil Spring Seal →
Elastomeric Rubber Bellow Conical Spring Mechanical Seals
A helically coiled compression spring wound to a tapered, conical profile rather than a constant diameter — the large end seats in the bore, the small end rides over the rod, and the coils telescope
View Conical Spring Seal →Both constructions share the same standard design principles — single mechanical seal, outside mounted, available with or without a bearing. The spring geometry is what decides how torque is transmitted and which duty each one suits best; see the comparison table below.
Rubber Bellow Mechanical Seal — Standard Specifications
Our standard BS12C range covers the following envelope. Duties outside this range are built to order — send your shaft diameter, pressure and temperature and we'll confirm.
| Parameter | Standard Range |
|---|---|
| Product code | BS12C |
| Shaft diameter | 25 mm to 80 mm |
| Pressure | Up to 12 bar (max.) |
| Temperature | 20°C to 180°C |
| Design | Standard design, single mechanical seal, outside mounted |
| Rotation | Independent of direction of rotation |
| Bearing | Available with or without bearing |
| Mounting | Outside mounted, top or side entry on agitators |
| Faces | Carbon, silicon carbide, ceramic, [Lecrolloy] |
| Elastomers | [NBR, EPDM, FKM, silicone — selected for media compatibility] |
What We Need to Quote Your Seal
Rubber bellow seals are matched to the equipment and duty, not sold as a single universal part. Send as much of this as you can — photographs of the existing installation fill most of the gaps.
| Parameter | What to Send | Why It Matters |
|---|---|---|
| Equipment type | Centrifugal pump, submersible pump, sewage pump, agitator or blender | Sets mounting style and expected duty |
| Shaft / sleeve diameter | Actual measured diameter at the seal | Sets bellow bore and spring size |
| Direction of rotation | CW, CCW or reversible | Confirms helical vs conical is the right fit |
| Mounting position | Top, side, or in-line on the pump shaft | Determines orientation of the seal assembly |
| Pressure | Normal and maximum operating pressure | Must stay within the 12 bar standard limit, or flags a custom build |
| Temperature | Operating and maximum temperature | Confirms elastomer compatibility (standard range 20°C–180°C) |
| Media | Water, sewage, effluent, chemical name, concentration | Decides elastomer and face material |
| Solids content | %, particle size, abrasiveness | Confirms bellow won't clog and face material holds up |
| Existing seal | Model, drawing, photos, sample, failure history | Enables a compatible replacement |
| Order details | Quantity, delivery location, required date | Production and dispatch planning |
Helical Coil vs Conical Spring: Choosing the Right Bellow Seal
Both constructions solve the same problem — sealing without a dynamic O-ring — but the spring geometry decides which one fits your duty.
| Comparison | Helical coil spring | Conical spring |
|---|---|---|
| Spring geometry | Constant-diameter open coil | Tapered coil, telescoping into itself |
| Torque transmission | Through the spring and spring holder | Through the elastomer collar |
| Best suited for | Water pumps, submersible and sewage pumps, effluent containing particles | Corrosive chemicals, high-temperature duties, hydrocarbon handling |
| Typical industries | Water and wastewater treatment, general pumping | Petrochemical, petroleum refining, pulp and paper |
| Key benefit | Won't clog on particles in the effluent stream | Self-aligning; reduces solid height while adding stability |
Both types run independent of direction of rotation. If your duty falls between these two descriptions — or outside the standard 25–80 mm / 12 bar / 180°C envelope — send your details and we'll confirm which construction, or a custom build, is the right fit.
Industries We Serve
Rubber bellow mechanical seals go wherever a conventional O-ring seal would wear out fast from shaft runout, solids, or media compatibility problems:
Why Buy from Ashish Seals India?
We've manufactured industrial sealing solutions in Mumbai since 2005, with the entire process under one roof:
Application-based seal selection by our own engineering team, matched to rotation direction and media
Custom design and development, including reverse engineering from a worn sample
CNC and VMC machining, seal-face lapping [checked to light-band flatness]
Component inspection, assembly and testing before every dispatch
Standard BS12C range plus custom builds beyond the 25–80 mm envelope on request
[Repair and reconditioning of existing seals]
Frequently Asked Questions
What is a rubber bellow mechanical seal?
A mechanical seal where an elastomer bellow — instead of a dynamic O-ring — acts as the secondary seal, sliding along the shaft or sleeve to absorb axial movement and shaft runout. This removes the fretting and hang-up problems a conventional O-ring seal can develop.
What's the difference between the helical coil and conical spring versions?
The helical coil version uses a constant-diameter open coil and transmits torque through the spring and spring holder — it won't clog on particles in the effluent. The conical version uses a tapered, telescoping coil and transmits torque through the elastomer collar, which self-aligns and protects the shaft from fretting.
Does direction of rotation matter?
No — both constructions are independent of direction of rotation, since torque isn't transmitted through a component that direction would affect.
What shaft diameter range do you cover?
Our standard BS12C range covers 25 mm to 80 mm. Larger or smaller shaft diameters can be built to order — send your details and we'll confirm.
What pressure and temperature can this seal handle?
The standard range covers up to 12 bar and 20°C to 180°C. Duties outside this envelope need a custom build — tell us your operating conditions and we'll confirm what's achievable.
Can a rubber bellow seal handle sewage or effluent with solids?
Yes — this is one of the most common duties for the helical coil spring version, which is built to avoid clogging on particles in the effluent stream.
Why choose a bellow seal over a standard O-ring mechanical seal?
An O-ring seal relies on the O-ring sliding along the shaft to compensate for movement — a point that can hang up, wear the sleeve, or seize on corrosive or dirty media. A bellow seal moves with the shaft instead, which is more forgiving on runout and less prone to fretting.
Which industries use rubber bellow mechanical seals?
Water and wastewater treatment, submersible and sewage pumps, petrochemical and refining, pulp and paper, and general chemical process pumps — anywhere shaft runout or solids make a conventional seal wear out fast.
Which materials are used for the faces and elastomer?
Carbon, silicon carbide and ceramic for the faces, with the elastomer selected for compatibility with your media and temperature. Tell us the process fluid and we'll confirm the right combination.
Can this seal be fitted with or without a bearing?
Yes — the standard design is available both ways, depending on whether your equipment already provides shaft support near the seal.
Can you manufacture a replacement from an old seal or sample?
Yes. We regularly develop replacements from a worn sample, a dimensional drawing, or good photographs plus the equipment details and operating conditions.
What is the price of a rubber bellow mechanical seal in India?
It depends on shaft diameter, spring type, materials and quantity — there's no fixed price list. Send your shaft diameter and duty details for a specific quotation.
How long does manufacturing take?
Standard BS12C sizes typically ship faster than custom builds. Share your required date with the enquiry and we'll confirm a lead time.
Do you supply outside Mumbai?
Yes — we supply across India [and export to the Middle East, Africa and Southeast Asia].
Request a Quote for a Rubber Bellow Mechanical Seal
New pump, submersible installation, or a seal that keeps failing on effluent or corrosive media — send us the shaft diameter, direction of rotation, media and existing seal details. Our engineers will confirm helical or conical construction, materials and any custom sizing, with a quotation to follow.