WF-BB11-70,Products,Wenzhou WeiFeng Technology Co., Ltd.

1. Product Overview

WF-BB11-70 four-bolt split threaded swing paddle flow sight indicator is a heavy-duty fully disassemblable inline visual flow monitor independently developed by TechWF. It adopts square four-bolt split clamping structure and internal thread connection, equipped with calibrated swing paddle dial to realize quantitative real-time flow observation. Widely deployed in sanitary food & pharmaceutical production, fine corrosive chemical transportation, large-scale precision agricultural irrigation, yacht and coastal marine auxiliary threaded pipeline systems.

This sight glass is precision cast from 304/316/316L stainless steel integrated square split T-body with symmetrical BSP/NPT internal thread ends, top embedded large round thick borosilicate observation window and high-visibility red corrosion-resistant PPS swing paddle. Standard internal thread design enables fast screw-on installation without welding or flanges; four hex socket bolts lock the square top sight frame, allowing full disassembly of the entire viewing assembly without cutting pipelines, supporting deep flushing of chemical crystals, fertilizer sludge and organic residues. It delivers real-time vertical top-down visual monitoring of flow velocity, pipeline emptying, clogging and reverse flow, fully protecting large anti-corrosion circulation pumps, sanitary reactors, agricultural main irrigation equipment and shipboard seawater cooling loops from dry-running, cavitation and irreversible corrosion contamination failure.

All finished products pass mandatory hydraulic burst pressure testing, long-cycle salt spray anti-corrosion aging testing, four-bolt uniform compression leakage testing and hot-cold alternating temperature cycle validation before factory shipment, ensuring stable zero-leak continuous operation under purified water, glycol, weak acid/alkali and low-salinity marine fluid media worldwide.

2. Premium Technical Specifications

Body Material: 304 / 316 / 316L stainless steel precision casting, matte brushed passivated anti-corrosion finish; full chemical inertness against seawater, mild acid/alkali and organic solvents, food-contact sanitary compliant
Connection Standard: Symmetrical BSP / NPT internal thread ends, full size DN15~DN50 customizable
Sight Window: Thick-wall impact-resistant round borosilicate top glass, 270° vertical downward full panoramic viewing with zero visual blind spots
Fastening Structure: Four symmetric hex socket stainless steel bolts for square top clamping frame, evenly distributed compression force to eliminate local glass stress cracking under pipeline pressure fluctuation and water hammer impact
Sealing Assembly: Double-layer EPDM / FKM composite O-ring seals; EPDM for clean water/food media, FKM for chemical solvent & brine media
Flow Indicator Core: Reinforced red PPS swing paddle with quantitative scale dial, acid/alkali/saltwater corrosion resistant, ultra-sensitive to micro low flow for early low-flow warning
Nominal Working Pressure: PN16 standard grade; PN25 reinforced marine high-pressure customized version available
Operating Temperature Range: -20℃ ~ +180℃
Flow Channel Design: Full straight-through full-bore inner cavity, zero extra pressure drop, seamless smooth inner wall minimizes medium residue adhesion and sediment buildup
Structural Feature: Integrated square split T-body with internal thread nozzles, square four-bolt top split frame, fully disassemblable without pipeline cutting for impeller replacement and complete cavity flushing & sanitization

3. Core Competitive Advantages

Square Split Heavy Cast Anti-Corrosion Stainless Steel Body

Integral stainless steel precision casting eliminates casting pores and internal stagnant dead zones, thickened square frame structure greatly improves overall rigidity to resist pipeline vibration and water hammer in heavy industrial and offshore platform environments. Smooth seamless inner surface effectively prevents food residue, pharmaceutical crystal and agricultural fertilizer buildup; 316L upgrade option provides outstanding anti-ocean salt fog performance for coastal high-salt threaded pipelines.
Universal Internal Thread Quick Installation Design

Identical standard internal threads on both inlet and outlet support bidirectional pipeline installation and direct screw-on assembly with all mainstream threaded pipe fittings, removing the need for transition adapters and on-site welding, drastically shortening construction cycles for large-bore threaded trunk line projects.
Four-Bolt Square Balanced Clamping System

Four evenly distributed hex bolts uniformly disperse clamping pressure on the top sight glass and composite gaskets, avoiding partial gasket extrusion and glass rupture under frequent pipeline pressure swings. Square outline realizes neat arrangement matching square instrument support racks in clean workshops and chemical plants.
Vertical Top-Down Panoramic Space-Saving Observation Window

Large round top borosilicate glass enables unobstructed vertical downward full-angle observation, requiring only vertical overhead clearance instead of horizontal side space. Perfectly suited for densely arranged threaded parallel trunk pipelines, low-ceiling clean rooms and compact marine engine room piping racks where side-view fittings are blocked by surrounding structures.
Zero Pressure Loss Full-Bore Unrestricted Flow Path

No internal protruding throttle structures generate additional pressure loss; the original pipeline design flow capacity is fully retained, meeting low-loss flow control requirements of fine chemical anti-corrosion production, food sanitary circulation and offshore desalination water trunk systems.
Chemical-Inert Quantitative Red PPS Swing Paddle Indicator

Custom molded PPS swing paddle with printed flow scale maintains stable rotation performance under long-term contact with acid, alkali and brine. Distinct red blade creates sharp visual contrast against transparent and turbid fluids, enabling operators to judge approximate flow volume intuitively and rapidly warn of low flow, pipeline dry-up and reverse medium flow to avoid corrosive medium leakage and costly pump/reactor breakdown losses.
Robust Four-Bolt Quick-Disassemble Maintenance Layout

After loosening four top hex bolts, the entire square top viewing frame, glass and swing paddle can be fully lifted out without detaching the whole fitting from the threaded pipeline. Maintenance staff can thoroughly flush accumulated chemical crystals, fertilizer scale and sludge, solving the difficult deep sanitization pain point of integrated sight glasses for dirty viscous corrosive media.
Compact Square Threaded Space-Saving Structure

One-piece square split threaded cylinder structure reduces overall installation length compared to oversized split sight glasses, saving horizontal linear layout space for parallel densely arranged threaded main pipelines in chemical workshops and marine engine rooms.

4. Global Cross-Industry Application Scenarios

Sanitary Food & Beverage Manufacturing: Factory central circulating cooling water threaded main pipelines, dairy, juice and purified drinking water sanitary threaded delivery lines; stainless steel anti-rust structure meets global food contact hygiene standards, square four-bolt design fits crowded horizontal production threaded pipelines.
Fine & Corrosive Chemical Engineering: Weak acid, weak alkali and organic solvent conveyance threaded trunk pipelines, lithium battery electrolyte circulation tubing, electroplating bath circulation lines; full stainless steel wetted surface avoids metal ion contamination of high-purity chemical products, split four-bolt design enables regular crystal sludge cleaning to prevent pipeline blockage and medium leakage accidents.
Large-Scale Precision Agriculture: Regional farm trunk water supply threaded pipelines, greenhouse main acidic/alkaline nutrient solution circulation threaded lines, central drip irrigation inspection threaded mains; anti-corrosion stainless steel resists long-term erosion of agricultural chemical media, convenient disassembly to clear fertilizer sediment guarantees uniform irrigation distribution and prevents crop yield loss.
Offshore & Yacht Marine Anti-Corrosion Engineering: Yacht engine room fresh water & cooling circulation threaded piping, offshore platform desalination auxiliary threaded trunk lines, marine aquaculture high-salinity brine dosing threaded pipelines; 316L stainless steel option withstands ocean salt fog and seawater corrosion, suitable for long-term service on vessels and coastal platforms.
Supplementary Application Fields: Industrial pure water treatment main equipment, large solar thermal circulation threaded pipelines, fire protection main water supply threaded lines, food-grade clean fluid transfer threaded trunk pipelines.

5. Customized Engineering Support Service

Material Customization: Standard 304 stainless steel, upgrade to 316 / 316L marine high anti-corrosion sanitary grade
Thread Standard Customization: GB, ANSI, DIN, BSP, NPT thread standards, customizable thread size
Pressure Grade Customization: Standard PN16, PN25 reinforced marine high-pressure variant, PN40 ultra-high pressure bespoke model
Sealing Material Matching: EPDM for clean water & food media, FKM fluororubber for acid, alkali and solvent transportation
Brand & Packaging Customization: Laser engraved customer LOGO on square body, anti-collision neutral export wooden case packaging; complete anti-corrosion material test certificates and pressure inspection reports provided for tender documentation
Caliber Customization: DN15, DN20, DN25, DN32, DN40, DN50 non-standard threaded pipe sizes available

6. Factory Premium Quality Control Standards

All WF-BB11 series threaded stainless steel flow sight indicators implement mandatory 100% full inspection prior to shipment. Standard factory testing items include hydraulic burst pressure testing, four-bolt uniform compression sealing leakage testing, salt spray long-cycle corrosion aging testing, swing paddle low-flow sensitivity testing and high-low temperature alternating cycle validation.

Complete stainless steel material certification, chemical corrosion resistance test reports and pressure vessel inspection documents can be supplied to support global chemical engineering tender reviews, offshore marine platform equipment audits and food factory sanitary compliance assessments.