Armstrong Series Pump 4300 Mechanical Seal

• Customization: Available
• Structure: Single End
• Pressure: Medium Pressure Mechanical Seals
• Model NO.: QT-ST
• Speed: General Speed Mechanical Seal
• Temperature: Temperature Mechanical Seal
• Performance: Corrosion
• Standard: Standard
• Type: HU1
• Balance: Unbalanced
• Delivery: in Stock
• Water Pump: Water Pump Seal
• Mud Pump: Mud Pump Seal
• Eagle Burgm: Eagle Burgm Seal
• Flowserve Type RO: John Crane St
• Armstrong Pump: Armstrong Pump Seal
• Transport Package: Customized Package
• Specification: standard
• Trademark: QT
• Origin: China
• HS Code: 84842000
• Production Capacity: 10000
• Package Size: 10.00cm * 10.00cm * 10.00cm
• Package Gross Weight: 1.000kg

Product Description

Parameter	Value/Description	Unit/Note
Model	QT-ST	Standard Temperature (ST) or Special Type mechanical seal
Seal Type	Single-Spring Unbalanced Seal	Cost-effective for general industrial applications
Face Materials	- Rotating: Carbon Graphite - Stationary: Silicon Carbide (SiC)	Graphite/SiC pairing for moderate wear resistance
Housing Material	Stainless Steel 304 (Standard) - 316L (Optional)	316L for corrosion resistance in chemical environments
Pressure Range	0 - 0.8	MPa	Suitable for low-to-medium pressure pumps (e.g., water, oil)
Shaft Diameter Range	20 mm - 60 mm	Common shaft sizes in pumps and mixers
Maximum Rotational Speed	2900	RPM	Matches standard motor speeds (50 Hz)
Temperature Range	-10°C ~ 120°C	Elastomer: NBR (standard); FKM up to 180°C (optional)
Leakage Rate	≤3.0	ml/h	Meets ISO 21049 standards for non-critical services
Media Compatibility	- Water, Mineral Oils, Aliphatic Hydrocarbons	Not recommended for strong acids, alkalis, or solvents
Installation Type	Insertion-Mounted (Simple Axial Fit)	Requires basic alignment; suitable for field repairs
Elastomer Material	NBR (Standard) - FKM (For High-Temp/Chemicals)	NBR: pH 6-8 compatibility; FKM: pH 0-14
Standards Compliance	ISO 21049, RoHS	Certified for environmental and safety requirements
Key Features	- Anti-Rotation Pin - Pre-Lubricated Faces - Economical Spare Parts	Simplified maintenance; ideal for non-critical processes

Mechanical seals for Armstrong pumps, Fybroc pumps(CECO, MET-PRO corp.), Aurora pumps, Bell & Gossett, Pentair pumps etc. brands.

Equivalent to John Crane/US SEAL VGXB2 and replacement seals used for Armstrong pump series 4300 (OE NO. 975002) and Fybroc pumps. 

Seals for Armstrong pumps: 
VG-975002304----1 1/8"--------975002-304
VG-975002334----1 5/8"--------975002-334
VG-975002374----2 1/8"--------975002-374
VG-975002394----2 5/8"--------975002-394

and seals for Bell & Gossett series 80-SC. 
VG-P75202-----1 1/4"---------P75202
VG-975002334---1 5/8"------P75203

and seals for Fybroc pumps 
VG-81375-------1 3/8"--------08976C010
VG-81376-------1 3/8"---------08976C100
VG-82125-------2 1/8"---------08975C010
VG-82126-------2 1/8"---------08975C070
VG-82875-------2 7/8"---------08974C010
VG-82876-------2 7/8"---------08974C010

Queeny Mechanical Equipment Co., Ltd. is an advanced fluid seal design and manufacturer. Our factory is located in Ningbo, Zhejiang, China. and our sales organization is located in Shanghai. We not only provide customers with products, but also provide customers with overall solutions including services to cope with the complex and challenging working conditions encountered by customers.


The main products we produce are: Component Seals, Dry Gas Seals, Mixer and Agitator Seals, Cartridge Seals, Metal Bellows Seals and Silicon Carbide products. Products are widely used in chemical, textile, food, pharmaceutical, metallurgy, printing and other mechanical equipment fields, and can undertake the design of non-standard and special seals.



1. Are we a factory or a trading company?
We are a factory only producing mechanical seals and we have our own marketing department  and also home market. The main market is 50% in China and 50% in European countries where most pumps factories located, we mainly supply to pump factories.

2. What are the payment methods?
We accept T/T, Western Union, Paypal, Made in China as your convenience.

3. How long is the delivery time?
Products in stock will be shipped within 48 hours. Standard seal 1-2 weeks. Custom seals are 3-4 weeks.

4. Could you offer sample ?
Yes, the sample could be sent to you with freight charge paid at your destination.

5. About our packaging type?
We have 2 kinds of packaging, one is with our brand, another one is white blank . with enough quantity, we could use your own logo in the package after your logo authorization.

6.I can not find our products in your catalog ,can you make customized products for us ?
Yes ,Customized products is available . Also, We have been adding new seals, there are many types we have not added in here yet, please send us the pump type or seals international code, we could identify the seals you need.