Bently NevadaThe Plant Asset Management Company SM

System 1 and Seal Leak Detection

Machinery Asset Management for Optimal Business Performance

Air quality regulations are driving this.Typical wording:

How are equipment leaks defined?

• Compressors: A leak occurs when a design-specific sensor indicates a failure of seal or barrier fluid systems

•Pumps in light liquid service: emissions of 10,000 ppm (or more) organic compounds, or there are indications of liquids dripping from the pump seal.

How must equipment leaks be monitored?

•Weekly: visual inspection of pump seals. Whenever liquid leaks are observed, the volatile organic compound concentration shall be monitored immediately.

•Quarterly: compressor seals, pipeline valves and pressure relief valves

•Annually: pump seals, pipeline valves in liquid service, and process drains.

How are repair schedules and procedures defined?

• Attempts at repair must be made within five days of detection of a leak, and must be completed within 15 days of leak detection.

Seal Leak Sensor System

Throat bushing

Vent line with existing

isolating valveExit orifice(to flare line)

SLD pressure transducer fitted to standard NPT tee

Throttle bushing(auxiliary sealing device)

Rotating seal member

stationary seal member

Seal chamber

Cross-section of single-stage shaft seal

Typical installationSingle stage mechanical seal

Flush line

Simple system architecture

Direct Input Transducers

Control Room

TIM Line or wireless connection

System 1 Host ComputerTo Plant

Information Network

Portable data collector for manual inspection routes

Optic fibre LAN

Field mounted DSM units

System 1 intuitive interface

Ideal platform to build plant-wide asset management program

• Division 1, 2 approved & designed to IP66

• Sensor may be exposed to H2S, H2SO4, Naphthenic acids, caustics, standard hydrocarbons

• Pressure rating

Operating - 30 psig (gage)

Proof Pressure - 300 psig

Burst Pressure - 400 psig

Seal Pressure Sensor and flexiTIM™ Module Features

Single stage shaft seal alternative strategies

1. SLD sensor on seal drain line

3. Thermocouple at end of shaft seal

2. SLD sensor on brg housing O/B sump drain

Seal Flush Line

Two stage shaft seal example

Barrier Fluid outlet

Barrier Fluid inlet

Potential pressure Sensor locations

Typical Parameters

• Steady-state vent line pressure: 0 to 10 psi (up to 70 kPa)

• Operators set alarms at 20 psi (140 kPa)

• Full Range of transducer is 30 psi (207 kPa)

• Seal temperature may change by + /- 10 to 20 degC with seal failure (depending of working fluid)

Bently NevadaThe Plant Asset Management Company SM

Seal Leak Detection Case Study

End-User Refinery

AustraliaTrendmaster Pump seal temperature sensor example

EHM Case Study – TM2000 Seal leak detection

ppm

Seal temperature trends Dec 17, 2003

General arrangement of pump

Temperature sensor at pump

Grooves on Carbon ring

Grooves on rotating face