Description

Scraper Passage Indicator

The Scraper Passage Indicator is a mechanically triggered device designed to monitor the passage of cleaning pigs through pipelines. When the pig passes through the pipeline, the indicator flag shifts from a horizontal to an upright position, providing a clear visual signal.

Construction and Materials

This pig passage indicator is installed using a 2″ flange. All parts in contact with the medium, including the flange sealing surface (or flange), can be made from carbon steel or stainless steel (such as 316 and 316L), depending on user requirements. This flexibility in material selection ensures compatibility with a wide range of industrial applications and environments.

Working Principle
The device operates with a bi-directional trigger pin installed at the end of an extension sleeve, which extends through a 2″ pipe close to the inner wall of the pipeline. When the cleaning pig passes by, it activates the trigger pin, which in turn pulls a linkage in the sealing sleeve. This action causes the indicator flag shaft to rotate 90° under the force of a torsion spring, changing the flag from a horizontal to an upright position. Users can reset the indicator flag by rotating it counterclockwise.

Main Specifications

• Operating Pressure:
  • Main body: 0.15 MPa
  • Standard configuration: 2″ ANSI 600# RF flange
  • Optional configurations: 300# and 900# RF flanges (or 1500# flange)
• Operating Temperature: -20 to 100°C
• Probe Length: 150 mm from the flange to the end of the extension sleeve, customizable upon request
• Remote Output Electrical Parameters:
  • Interface: 3/4 NPT
  • Switch Type: SPDT or DPDT
  • Switching Capacity: 3A/24VDC

Installation Method

Before installing the pig passage indicator, ensure the pipeline has a pre-installed flange that meets the installation requirements of the instrument. Align the two flange holes with the pipeline direction. Use a 3-5 mm thick sealing gasket between the flanges. Ensure the trigger pin direction faces the pipeline flow direction (i.e., the notch aligns with the pipeline direction) or the indicator flag shaft is perpendicular to the pipeline direction. Insert the extension sleeve into the pipeline and secure it with bolts. If the method flange obstructs bolt insertion, loosen the four bolts on the method flange, rotate it to the desired angle, and then insert the bolts. After installing the main flange, restore the method flange to its original state.

Maintenance

The part of the instrument above the flange can be disassembled under pressure, but since the mechanical components in this section are not easily damaged, disassembly is not recommended. The O-rings used for sealing in the section below the flange are prone to wear and tear. Prolonged use under pressure can reduce their lifespan. If leakage occurs, it is advisable to return the device to the manufacturer for repair or replacement.

Additional Notes

• All fluid-contacting parts and flanges are made of 316SS.
• Connection flange: HG20617-97 2″ 1500LB RJ
• Distance from the trigger pin tip to the inner wall of the pipeline: 40±1 mm

The Scraper Passage Indicator is an essential tool for monitoring pipeline cleaning processes, providing reliable and clear indications of pig passage. Its robust construction and versatile material options make it suitable for various industrial environments, ensuring both durability and efficiency.

Application Industries of Scraper Passage Indicator

Oil and Gas Industry

• Pipeline Maintenance: In oil and gas transportation pipelines, cleaning pigs remove accumulated debris and impurities to ensure smooth fluid flow. The SN3Ⅰ—TQZ Flag-Type Pig Passage Indicator precisely monitors the passage of cleaning pigs, ensuring effective pipeline cleaning and maintenance.
• Pipeline Inspection: Regular use of cleaning pigs for internal pipeline inspections provides real-time feedback from the indicator, helping to detect internal wear, corrosion, or other potential issues.

Chemical Industry

• Chemical Transport: In chemical plants, pipelines often work to transport various chemicals. The pig passage indicator ensures the smooth passage of cleaning pigs, maintaining pipeline cleanliness and preventing cross-contamination between different chemicals.
• Production Process Maintenance: Keeping pipelines unobstructed is crucial during chemical production. The pig passage indicator helps operators monitor the cleaning pig’s operation, ensuring continuous and stable production processes.

Water Treatment Industry

• Wastewater Treatment: In wastewater treatment plants, pipelines transport treated water and sludge. The pig passage indicator effectively monitors the passage of cleaning pigs, ensuring there are no blockages or buildups, and maintaining high system efficiency.
• Drinking Water Transport: In drinking water transport systems, regular pipeline cleaning ensures water quality safety. The pig passage indicator provides clear visual signals, ensuring the smooth passage of cleaning pigs through the pipelines.

Food and Beverage Industry

• Hygiene Requirements: During food and beverage production, pipelines must remain highly clean. The pig passage indicator helps monitor the passage of cleaning pigs, ensuring no residues remain inside the pipelines, meeting hygiene standards.
• Production Line Cleaning: Used for cleaning and maintaining production lines, it ensures no cross-contamination between different products, improving product quality.

Pharmaceutical Industry

• High Cleanliness Requirements: Pharmaceutical production requires extremely high cleanliness inside pipelines. The pig passage indicator ensures effective cleaning of the pipeline interior, preventing drug contamination.
• Process Control: It helps operators monitor the cleaning pig’s operation in real-time, ensuring safe and stable production processes.

Power Generation Industry

• Cooling System Maintenance: In power plants, pipelines are used to transport cooling water. The pig passage indicator ensures the smooth passage of cleaning pigs, maintaining the efficient operation of cooling systems.
• Fuel Transport: In fuel transport pipelines, the pig passage indicator ensures the cleaning pigs pass through, preventing pipeline blockages and ensuring continuous fuel supply.