Objectives

The primary objective is to design, manufacture, supply, install, commission, and validate a fully integrated temperature response test rig for laboratory use. The system must enable precise safety-valve performance testing and mixer temperature-control sensitivity assessments under strictly controlled thermal and pressure conditions.

Scope of Work

• Provide a complete, turnkey operational system rather than individual components.
• Conduct safety-valve temperature response testing, including controlled heating and cooling of pressurised water.
• Measure and record water temperature adjacent to the safety-valve thermostatic probe.
• Maintain controlled temperature ramp rates between 1.5 °C/min and 3.0 °C/min.
• Manage inlet pressure at 300 ± 10 kPa and stabilise initial mixed-water temperature at 30 °C.
• Deliver, install, and commission the rig at the designated SABS facility.
• Verify all system functions during commissioning and provide structured training for three client staff members.
• Supply comprehensive system documentation and calibration certificates.

Technical Requirements

• Test Vessel: Rated for maximum anticipated pressure and temperature during testing.
• Safety-Valve Connection: Accommodates multiple valve sizes, allows horizontal installation and full submersion, prevents leakage under pressure, and includes safe discharge drainage with interchangeable adapters.
• Temperature Sensing: Pt100 RTD Class A or better, 0–100 °C range, ±0.2 °C accuracy, 0.1 °C resolution. Positioned within 10 mm of the thermostatic probe midpoint using an adjustable, non-interfering mount.
• Data Acquisition & Recording: Continuous logging of temperature, time, rate of change, test phases, and exact valve open/close temperatures. Real-time graphical interface (temperature vs. time) preferred.
• Heating & Cooling Systems: Electrically powered heating with PLC-regulated power output to maintain target ramps. Automated cooling capable of matching ramp rates without compromising system pressure or causing unsafe fluctuations.
• Pressure Control: Digital pressure transducers with ±1 % accuracy, continuous monitoring, and automated alarms/interlocks exceeding safe operating limits.
• Air Removal: Filling mechanism designed to minimise air entrapment in the test vessel.
• Discharge Detection: Electronic sensing method to trigger PLC signals for valve opening and closing, with corresponding temperature and time recorded.
• Mixer Test Circuit: Separate circuit for sensitivity testing, featuring controlled inlet pressure, temperature stabilisation, and angular movement measurement (5 ± 0.1° hot direction).
• Calibration: All measurement instruments must be calibratable and traceable to recognised national or international standards. Certificates required upon commissioning.

Skills and Capability Requirements

• Proven engineering and manufacturing expertise in custom laboratory test rig design and automation.
• Proficiency in PLC programming, sensor integration, and data acquisition software development.
• Experience in precision equipment installation, performance validation, and safety interlock implementation.
• Ability to deliver structured technical training to end-users.
• Compliance with South African public procurement regulations, including Central Supplier Database registration, valid BBBEE documentation, tax compliance verification, and submission of prescribed Standard Bidding Document (SBD) forms.

Key Terms and Concepts

80/20 Preference Points System: A South African procurement evaluation model where 80 points are allocated for competitive pricing and 20 points for socio-economic transformation goals, such as black ownership, women-owned enterprises, or businesses owned by persons with disabilities.

PLC Control: Programmable Logic Controllers used to automate and regulate thermal ramps, pressure maintenance, sensor data logging, and safety interlocks in real time.

Traceable Calibration: Verification that measurement instruments meet specified accuracy standards, with certification linked to nationally or internationally recognised metrology references.

SBD Forms: Standardised South African government bidding documents used to verify bidder eligibility, disclose potential conflicts of interest, and formally claim preference points.