M117U

Product features and advantages

Internal-mounted, single-end, single-spring, non-balanced, lug drive, arbitrary rotation direction, compliant with EN 12756 (DIN 24960) and ISO 3069 standards.

Parameter

Applicable working conditions

1.Water treatment: municipal sewage, industrial wastewater, circulating water, seawater desalination; clean water, acid-alkali water and flocculant solution with trace particles (<1%).

2.Chemical / pharmaceutical: neutral and corrosive media with low to medium viscosity (≤ 3000 mPa·s), such as methanol, ethanol, citric acid, phosphate, dilute acids and alkalis.

3.Metallurgy / electroplating: cooling circulating water, pickling wastewater, low-abrasion liquids containing heavy metal ions.

4.General industry: clean water, low-temperature hot water, hydraulic oil, lubricating oil, emulsion and other non-highly corrosive, low-abrasion applications.

Not applicable for:

• High abrasion (solid particles >5%, high-hardness slurry), high vacuum (< 0.05 MPa), ultra-high pressure (> 1.6 MPa), ultra-high temperature (> 150 ℃)
• Strongly corrosive media (concentrated hydrochloric acid, hydrofluoric acid, chlor-alkali solution): upgrade to SiC-SiC + FFKM + Hastelloy required
• Easily crystallizing, high viscosity (> 5000 mPa·s) or long-fiber containing media (may cause spring seizure and face wear)

Additional Selection Recommendations

• Trace particles (0.5%–1%): Use graphite + SiC, with API Plan 11 flushing and filtration
• Weakly corrosive service: FKM secondary seal; strongly corrosive service: PTFE/FFKM + 316L metal parts
• High temperature (80–120 ℃): Adopt high-temperature FKM or metal bellows structure with cooling plan

Application areas/scenarios

1. Water treatment / Environmental protection: municipal sewage, industrial wastewater, circulating water, clean water, seawater, aqueous media with trace particles (<1%), low abrasion

2. Petrochemical / Pharmaceutical: oils, solvents, methanol, ethanol, acetone, dilute acids and alkalis, salt solutions, medical liquids, syrup and other neutral to weakly corrosive, non‑crystallizing, low‑viscosity media (≤3000 mPa·s)

3. General industry: clean water pumps, pipeline pumps, chemical centrifugal pumps, screw pumps, oil pumps, papermaking equipment, etc., suitable for conventional working conditions without severe abrasion, high vacuum or severe vibration

4. Food / Papermaking: clean process media, pulp black liquor (low abrasion); food‑grade materials (316L + PTFE + SiC) are available

FAQ

1. Leakage (most common issue)

• Leakage at static sealing face: Check if the stationary seal gasket (O‑ring, V‑ring) is aged, deformed or mismatched in size. Replace it with a media‑resistant and temperature‑resistant gasket of the same specification. If the fit clearance between the stationary ring and the gland is too large, re‑machine or replace the stationary ring.
• Leakage at dynamic sealing face: Inspect the sealing end faces of the rotating and stationary rings for scratches, wear or chipping. Minor scratches can be repaired by lapping; replace the seal rings directly if severely damaged. Also verify the spring compression: add gaskets if insufficient, reduce gaskets if excessive.
• Leakage at shaft sleeve / shaft fit: Check for damage to the shaft sleeve gasket, or excessive fit clearance between shaft sleeve and shaft. Replace the gasket or re‑grind the shaft sleeve.

2. Abnormal wear

• Excessive end face wear: Install a filter if caused by particulate impurities in the medium. For insufficient lubrication, use self‑lubricating seals such as impregnated graphite rings, or introduce external flushing liquid (e.g. clean same medium).
• Shaft sleeve wear: Replace the shaft sleeve with wear‑resistant material, and adjust the concentricity between the seal chamber and the shaft to avoid eccentric wear.

3. Overheating and Burning

• Excessively high temperature in seal chamber: Check if the cooling system is clogged and clean the cooling lines. If the medium temperature is inherently high, use high-temperature resistant seal materials (such as silicon nitride ceramic rings and fluororubber gaskets).
• Poor end-face contact due to spring failure: Replace fatigued or corroded springs, select corrosion-resistant spring materials such as stainless steel, and ensure uniform spring compression.

4. Vibration and Abnormal Noise

• Misalignment: Recalibrate the concentricity between the pump shaft and motor shaft, and adjust the radial runout of the seal chamber and shaft to within allowable limits.
• Loose parts: Check whether the gland bolts and drive pins are loose, tighten the bolts evenly to the specified torque, and replace worn drive pins.

5. Short Service Life of Seals

• Mismatch between material and medium: Replace seal materials according to medium characteristics (e.g., Hastelloy and PTFE for corrosive media; silicon carbide for high-temperature media).
• Improper installation: Operate in strict accordance with installation specifications, avoid impact or scratches on the seal pair end faces, and ensure no impurities enter the seal chamber during installation.