Balanced and Unbalanced PTFE Wedge Mechanical Seals

MIAOYU offers Model 58B balanced and unbalanced PTFE wedge seals engineered for extreme chemical resistance in corrosive, high-temperature, and high-pressure applications. The unbalanced design reliably serves general chemical duty up to 12 bar, while the balanced version features a stepped sleeve and anti-rotation lugs to handle pressures up to 35 bar with reduced face heat generation and lower wear. Both variants utilize a chemically inert PTFE wedge as the primary sealing element, operating across -30°C to 200°C, speeds up to 25 m/s, and pressures up to 2.5 MPa.

Ideal for reactor agitators, chemical pumps, solvent handling, and food processing equipment where reliability under aggressive media is critical.

Model:58B

WhatsApp Now

Key Features

• Versatile Options: Choose Unbalanced for general chemical duties (up to 12 bar) or Balanced for high-pressure/low-SG fluids (up to 35 bar).

• Reduced Heat Generation (Balanced): The balanced geometry significantly lowers face friction heat, preventing fluid vaporization and extending face life.

• Chemical Inertness: Both versions of this ptfe mechanical seal utilize the same high-purity PTFE wedge technology for maximum corrosion resistance.

• Stepped Sleeve Design: For balanced seals, we provide the necessary stepped sleeve to achieve the hydraulic balance ratio without modifying your pump shaft.

• Anti-Rotation Lugs: Heavy-duty drive lugs are incorporated to prevent face rotation under the high torque loads common in high-pressure sealing.

Technical Specs		Materials
Mediums	Petroleum, chemical solvents, medium corrosion.	Stationary Ring	Ceramic/Sic/TC
Temperature	30℃ to 200℃	Rotary Ring	Carbon/Sic/TC
Pressure	≤2.5MPa	Secondary Seal	PTFE
Speed	≤25m/s	Spring and Metal Part	Stainless Steel

Product Specifications

Metric Shaft Size D1	Size Code	D2	D3	D7	L1	L4	L3
14	0140	18	32	25	30.7	12	6
16	0160	20	34	27	30.7	12	6
18	0180	22	36	33	31.7	13.5	6.5
20	0200	24	38	35	31.7	13.5	6.5
22	0220	26	40	37	31.7	13.5	6.5
24	0240	28	42	39	34.4	13.5	6.5
25	0250	30	44	40	34.7	13	7
28	0280	38	47	43	37.7	12.5	7.5
30	0300	35	49	45	38.2	12	8
32	0320	38	54	48	38.2	12	8
33	0330	38	54	48	38.2	12	8
35	0350	40	56	50	38.2	12	8
38	0380	43	59	56	39.7	13	10
40	0400	45	61	58	39.7	13	10
43	0430	48	64	61	39.7	13	10
45	0450	50	66	63	39.7	13	10
48	0480	53	69	66	39.7	13	10
50	0500	55	71	70	44.2	13.5	11.5
53	0530	58	78	73	44.2	13.5	11.5
55	0550	60	80	75	44.2	13.5	11.5
58	0580	63	83	78	49.2	13.5	11.5
60	0600	65	85	80	49.2	13.5	11.5
63	0630	68	88	83	49.2	13.5	11.5
65	0650	70	90	85	49.2	13.5	11.5
70	0700	75	95	92	55.7	14.5	13.5
75	0750	80	104	97	55.7	14.5	13.5
80	0800	85	109	105	55.2	15	13
85	0850	90	114	110	60.2	15	13
90	0900	95	119	115	60.2	15	13
95	0950	100	124	120	60.2	15	13
100	1000	105	129	125	60.2	15	13

Workshop

Here is the revised paragraph with "balanced and unbalanced mechanical seal" naturally integrated:

This workshop is equipped with professional processing equipment and integrated with standardized material warehousing management, enabling a one-stop production process from precision machining of balanced and unbalanced mechanical seal components to finished product delivery. Dedicated production lines for each balanced and unbalanced mechanical seal configuration ensure part machining accuracy and production efficiency, meeting various high-specification manufacturing requirements for chemical, pharmaceutical and high-temperature pump applications.

Metal Bellows Seals for High Temperature Pumps 606

Product Research, Development and Testing

Our Product R&D and Testing focuses on optimizing seal performance through advanced simulation and material analysis. All balanced and unbalanced mechanical 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

High-Pressure Reactor Feed: A chemical plant needed to seal a reactor feed pump operating at 25 bar. Unbalanced seals were wearing out in weeks. We supplied a Balanced PTFE Wedge Seal. The reduced face closing force lowered the operating temperature, stopping the premature wear.

Testimonials

We upgraded from unbalanced to balanced mechanical seals on our boiler feed chemical injection pumps. The reliability gain was immediate.

—Reliability Engineer, Power Station

FAQs

Q: When should I use a Balanced seal?

A: You should switch to a Balanced seal if your operating pressure exceeds 10-12 bar, or if you are pumping fluids with a low specific gravity (volatile fluids) where heat generation could cause flashing.

Q: What is the difference between balanced and unbalanced PTFE wedge mechanical seals?

A: An unbalanced mechanical seal has the full hydraulic pressure acting to close the faces, making it suitable for general chemical duties up to 12 bar. A balanced mechanical seal uses a stepped sleeve to reduce the hydraulic closing area, lowering face contact pressure—enabling operation up to 35 bar and with low-specific-gravity fluids without overheating or vaporizing the fluid film.

Q: When should I choose a balanced vs unbalanced PTFE wedge seal for my pump?

A: Choose the unbalanced version for standard chemical transfer, solvent recovery and waste acid service at pressures below 12 bar. Choose the balanced version for high-pressure reactor feed pumps, boiler circulation, liquid injection and any application involving propane, butane, ammonia or other low-SG fluids where face overheating and fluid flashing are risks. Both share the same PTFE wedge chemical resistance.

Q: Does the balanced PTFE wedge seal require pump shaft modification?

A: No. We supply the necessary stepped sleeve with each balanced mechanical seal to achieve the correct hydraulic balance ratio—the sleeve slips onto the existing shaft without machining, welding or diameter reduction. The anti-rotation lugs on both versions handle the high torque loads typical of PTFE wedge drive without slipping or fretting the shaft.