This Type 301 rubber bellows mechanical seal is a direct-dimension replacement designed for legacy APV® end-suction centrifugal water pumps — including certain Premier series models and early World Series utility pump variants that utilize a bellows-type seal chamber. Unlike modern wave-spring hygienic cartridge seals (APV W+ type), this type 301 mechanical seal features a one-piece nitrile (NBR) or EPDM rubber bellows rotating assembly that combines the secondary seal, drive mechanism, and spring function into a single component.
The flexible bellows design compensates for shaft run-out, vibration, and minor misalignment common in aging pump installations — eliminating the need for set screws or drive pins that can slip on worn shafts. The standard face combination of resin-impregnated carbon graphite rotating against a 99.5% alumina ceramic stationary seat provides reliable sealing for clean water, softened water, cooling water, and light mineral oils at temperatures up to 100°C (NBR) or 120°C (EPDM).
Available in common fractional-inch shaft diameters from 3/8″ to 1″ (9.5–25.4 mm), this type 301 mechanical seal is a cost-effective, drop-in replacement for maintaining legacy APV pump installations without expensive conversion to modern cartridge seal chambers.
Key Features
• Type 301 Style: An aftermarket replacement for the specific "Type 301" style seal used in legacy APV water and simple transfer pumps.
• Rubber Bellows Design: Features a robust rubber bellow that drives the rotary face, similar to a Type 21 but dimensioned for APV housings.
• Economical Repair: A cost-effective solution for extending the life of older APV pumps in water service.
• Self-Aligning: The flexible rubber bellow compensates for shaft end-play and misalignment common in older, worn pumps.
• Simple Installation: One-piece rotary unit slides onto the shaft; no set screws to tighten or drive pins to align.
Applications & Compatible Equipment
Compatible Pump Types:
APV® Premier series (select models with bellows seal chamber — not W+ hygienic)
APV® World Series (early utility water versions, pre-W+ transition)
Other legacy end-suction centrifugal pumps adopting Type 21/301 dimensional envelope and bellows chamber profile
Typical Media:
Clean water, softened water, cooling tower water, boiler feed water (≤100°C NBR / ≤120°C EPDM), light mineral oils and coolants (NBR version only), non-potable process water
Industries:
HVAC / building services, industrial cooling, light process water transfer, agricultural irrigation, general utility pumping
Technical Specs | Materials | ||
Mediums | Water, oil and weakly-corrosive mediums | Stationary Ring | Ceramic/Sic/TC |
Pressure | ≤0.5MPa | Rotary Ring | Carbon/Sic/TC |
Temperature | -20℃ to 100℃ | Secondary Seal | NBR/EPDM/Viton |
Speed | ≤10m/s | Spring and Metal Part | Stainless Steel |
Product Specifications
| D1 (inch) | Size Code | D3 | D7 | L1 | L4 |
| 0.375 | 0095 | 23.8 | 22.23 | 16.08 | 6.35 |
| 0.375A | 0095A | 26.97 | 25.4 | 16.86 | 7.93 |
| 0.500 | 0127 | 26.97 | 25.4 | 16.86 | 6.35 |
| 0.500A | 0127A | 26.97 | 25.4 | 16.86 | 7.93 |
| 0.625 | 0158 | 30.94 | 31.75 | 18.44 | 10.31 |
| 0.750 | 0191 | 34.11 | 34.93 | 18.44 | 10.31 |
| 0.875 | 0222 | 42.85 | 41.28 | 20.82 | 11.1 |
| 1.000 | 0254 | 42.85 | 41.28 | 20.82 | 11.1 |
Workshop
This workshop is equipped with professional processing equipment and integrated with standardized material warehousing management, enabling a one-stop production process from precision machining to finished product delivery. It ensures part machining accuracy and production efficiency, meeting various high-specification manufacturing requirements.
Product Research, Development and Testing
Our Product R&D and Testing focuses on optimizing seal performance through advanced simulation and material analysis. All seals undergo rigorous trials, including thermal cycling and pressure tests, to ensure durability, minimal leakage, and long service life in demanding industrial environments.
Industry Solutions
Case Study
Waste Water Treatment: An older APV pump in a water treatment facility was leaking. OEM parts were obsolete. We identified it as a Type 301 style and supplied this replacement. It fitted perfectly and sealed the pump, saving the cost of a new pump.
Testimonials
Thought we'd have to scrap our old pumps until we found this seal. Works great for general water transfer.
—Facility Tech, Water Plant
FAQs
Q: Is this for sanitary use?
A: The Type 301 design with a rubber bellow is generally for utility water or non-sanitary applications. For food product contact, we recommend the wave spring or hygienic seal styles (like the W+ series).
Q: Will this Type 301 seal fit my APV W+ (World Plus) hygienic pump?
A: No. APV W+ pumps use a wave-spring hygienic cartridge seal with a clamp ring retention system — completely different from the bellows-type seal chamber required for Type 301. If you have a W+ pump, please see our APV W+ hygienic seal page. If unsure, send us a photo of your existing seal or pump nameplate for identification.
Q: My APV pump has a badly worn shaft — can this seal still work?
A: The rubber bellows design is more forgiving of shaft wear than spring-loaded seals. However, if shaft groove depth exceeds 0.05 mm, we strongly recommend installing a shaft sleeve or replacing the shaft section before fitting a new seal for reliable long-term performance.
Our company is specialized in the production of sealing materials, mechanical seals , cartridge seals.
E-mail: gechacha@aliyun.com
Mobile: +86-18758835650
WhatsApp: +86-18758835650
Add: No8-2, Jinsha road Yuelin Street, Fenghua District, Ningbo, Zhejiang
