WF-FQ41-4,Products,Wenzhou WeiFeng Technology Co., Ltd.

1. Product Overview

WF-FQ41-4 flange-type straight flow sight indicator is a heavy-duty industrial pipeline visual flow monitor independently developed by TechWF. It adopts integrated precision cast 304 stainless steel straight cylindrical body, standard GB/ANSI flanged connection at both ends, top quick-release circular borosilicate sight window and built-in dual-color red & blue anti-corrosion PP floating balls. Standard flange interface realizes high-strength sealed pipeline matching, applicable to medium-large caliber industrial process pipelines, widely deployed in precision machinery cooling, medium corrosive fine chemical, large-scale agricultural irrigation, central HVAC heating, offshore yacht and coastal marine industrial piping systems.

This sight glass is integrally seamless cast from 304 stainless steel streamline straight cavity, both ends equipped with standard multi-hole flanges for bolt fastening installation, with uniform stress and stable sealing under high pressure. The top detachable round transparent observation chamber holds dual high-contrast float balls; when medium flows along the built-in flow direction mark, fluid buoyancy lifts the two float balls synchronously to visually confirm normal medium circulation; if flow cuts off, empties or reverses, float balls sink to the bottom to give clear early warning. It delivers reliable full-flow visual monitoring for industrial circulating pumps, chemical dosing pipelines, farm irrigation main lines and marine equipment cooling loops, effectively avoiding pump dry-running, pipeline blockage and heat equipment overheating failure.

All finished units pass hydraulic burst pressure testing, salt spray anti-corrosion aging testing, flange bolt uniform compression sealing leakage testing and hot-cold alternating cycle validation before factory delivery, maintaining stable zero-leak continuous operation under purified water, glycol, weak acid/alkali and low-salinity seawater media worldwide.

2. Premium Technical Specifications

Body Material: 304 stainless steel precision seamless casting, matte passivated anti-rust finish, food & marine anti-salt corrosion certified; 316/316L optional for strong corrosive medium
Connection Standard: Double-end standard flanged connection (GB HG20592 / ANSI B16.5), customizable DN25~DN100
Sight Window: Quick detachable circular thick high-pressure resistant borosilicate glass, 270° overhead panoramic omnidirectional viewing without blind spots
Indicator Core: Dual-color red & blue PP floating balls, lightweight, chemical inert, rises synchronously under fluid buoyancy
Sealing Assembly: Double-layer reinforced EPDM / FKM composite gaskets; EPDM for clean water & edible media, FKM for weak acid/alkali solvent & brine media
Nominal Working Pressure: PN16 standard grade; PN25 high-pressure reinforced industrial version optional
Operating Temperature Range: -10℃ ~ +120℃
Flow Channel: Streamline straight full-bore inner cavity, zero extra pressure drop, polished smooth inner wall reduces crystal, limescale and fertilizer sediment adhesion
Structural Feature: Straight cylindrical integrated flanged body, thread lock quick-release top sight cover, fully disassemblable to extract dual float balls for deep flushing without pipeline cutting

3. Core High-End Competitive Advantages

Integral Seamless Cast 304 Stainless Steel Streamline Straight Anti-Corrosion Body

One-piece seamless precision casting eliminates casting pores and internal stagnant dead zones; streamline flow path optimizes fluid dynamics and minimizes flow resistance. Matte passivation delivers outstanding rust resistance in humid factory and coastal salt fog environments, far superior to brass fittings for acid, alkali and saltwater industrial working conditions. Smooth seamless inner surface effectively inhibits medium sludge buildup.
Standard Multi-Hole Flange Connection, High Pressure & High Sealing Safety

Dual-end standard industrial flanges with evenly distributed bolt holes uniformly disperse pipeline pressure, avoiding thread loosening leakage risk of threaded sight glasses; compatible with mainstream national and international standard flanges, easy on-site pipeline matching for large industrial projects.
Quick-Release Circular Sight Window, Convenient Full-Cavity Maintenance

Thread lock quick-release top cover can be manually disassembled without special tools, complete extraction of dual float balls for deep cleaning of crystal, fertilizer and oil sediment, ideal for long-cycle continuous production chemical and agricultural media pipelines prone to fouling.
Dual-Color Float Ball High-Contrast Intuitive Flow Visualization

Distinct red & blue dual float balls create sharp visual contrast against transparent glass, operators can identify flow status clearly from long distance even in dim workshop environment. Pure buoyancy-driven mechanical design without fragile springs or swing paddles, ultra-low failure rate and extended service life.
Zero Pressure Loss Streamline Full-Bore Unrestricted Flow Path

No protruding throttle obstacles inside the straight cavity, fully retains original pipeline flow capacity, perfectly matching low-loss flow control demands of precision machine cooling, fine chemical continuous dosing and agricultural main irrigation flanged piping systems.
Chemical-Inert Lightweight Dual Float Ball Assembly

PP float balls resist weak acid, alkali and light saltwater erosion, ultra-lightweight with sensitive response to tiny flow fluctuations, no jamming or sticking after 24-hour long-term continuous industrial operation.
270° Overhead Omnidirectional Observation, No View Blockage

Large circular transparent glass realizes wide-range overhead viewing, no matter horizontal or vertical pipeline layout, operators can observe float ball state without adjusting installation orientation.
Heavy-Duty Reinforced Integrated Structure, Wide Industrial Compatibility

Thickened flange and cylinder wall enhance overall structural rigidity, stable under pressure fluctuation and temperature cycling; customizable caliber, flange standard and material to meet chemical, marine, agricultural, heating multi-industry customized demands.

4. Global Cross-Industry Application Scenarios

Precision Industrial Machinery & Central HVAC Cooling

Large CNC equipment cooling flanged pipelines, injection molding production line auxiliary circulation lines, building central heating main branch water pipes, solar multi-loop hot water main tubing; standard flange interface adapts to large industrial process piping network.

Medium Corrosion Light Fine Chemical Industry

Weak acid/alkali solvent flanged main pipelines, continuous reagent delivery production lines, water-based coating circulation loops; full detachable sight window facilitates regular crystal sludge removal to prevent pipeline clogging and medium leakage safety accidents.

Large-Scale Precision Agriculture

Farm central nutrient solution irrigation main flanged lines, large fertilizer mixing station dosing pipelines, greenhouse group watering trunk lines; full cavity flushing avoids long-term fertilizer sediment buildup leading to uneven irrigation.

Offshore Yacht & Coastal Marine Anti-Corrosion Industrial Systems

Medium-sized yacht main engine cooling flanged circulation lines, coastal aquaculture factory low-salinity water main piping, offshore platform light cooling water sub-loops; 304/316 stainless steel passivation layer withstands long-term ocean salt fog splash erosion.

Supplementary Auxiliary Fields

Industrial pure water treatment main flanged pipelines, fire protection central clean water trunk lines, large compressor & hydraulic station auxiliary cooling circulation piping.

5. Customized Engineering Support Service

Material Customization: Standard 304 stainless steel, upgrade to 316 / 316L high anti-corrosion marine sanitary grade
Flange Standard Customization: Custom GB HG20592, ANSI B16.5, JIS flange standards, DN25/DN40/DN50/DN65/DN80/DN100 calibers
Pressure Grade Customization: PN16 standard, PN25 high-pressure industrial reinforced variant
Sealing Material Matching: Food-grade EPDM for water & edible media, FKM fluororubber upgrade for weak acid/alkali organic solvent transportation
Brand & Packaging Customization: Laser engraved customer LOGO on cylinder body, neutral anti-collision export wooden case packaging; complete material & pressure test certificates provided for tender documentation
Flow Indicator Customization: Single red float ball / dual red-blue float ball optional

6. Factory Premium Quality Control Standards

All WF-FQ41-4 flanged straight float ball sight indicators implement mandatory 100% full inspection prior to shipment. Standard factory testing items include hydraulic burst pressure test, flange bolt uniform compression sealing leakage test, salt spray long-cycle anti-corrosion aging test, float ball low-flow sensitivity test and cold-hot alternating cycle validation.

Complete stainless steel material certification, sanitary inspection reports and full pressure vessel test packages can be supplied to support global machinery cooling, light chemical, agricultural and coastal marine engineering tender reviews and equipment safety compliance audits.