WF-BB11-29,Products,Wenzhou WeiFeng Technology Co., Ltd.

1. Product Overview

WF-BB11-29 internal thread swing paddle flow sight indicator is a compact mini inline visual flow monitor independently developed by TechWF, designed for small-bore threaded branch pipelines requiring intuitive flow magnitude feedback. Widely used in sanitary fine chemical, heating HVAC, precision agriculture water supply, yacht and coastal marine auxiliary circulation systems.

This sight glass adopts precision cast 304/316 stainless steel integrated cylindrical T-body with symmetrical NPT/BSP internal thread ends, top embedded thick borosilicate observation window and calibrated swing paddle with scale dial. Standard internal thread realizes fast screw-on installation without welding or flanges; the weighted swing paddle deflects proportionally to flow rate, with printed numerical scale for visual quantification of fluid volume. It supports real-time observation of flow status, pipeline cut-off, backflow and low-flow warning, effectively protecting small circulation pumps, micro chemical reactors, agricultural branch irrigation equipment and ship auxiliary cooling loops from dry-running and cavitation damage.

Every unit undergoes hydraulic burst pressure testing, salt spray anti-corrosion aging testing, thread sealing leakage testing and hot-cold cycle verification before delivery, maintaining stable zero-leak performance under purified water, glycol, weak acid/alkali and low-salinity seawater media worldwide.

2. Premium Technical Specifications

Body Material: 304 / 316 stainless steel precision casting, matte passivated anti-rust finish, food & marine sanitary compliant
Connection Standard: BSP / NPT internal thread, available sizes DN15~DN50
Sight Window: Thick high-pressure resistant round borosilicate glass, 270° vertical full top viewing
Internal Indicator: Weighted swing paddle with yellow quantitative scale dial, proportional deflection with flow velocity
Sealing Structure: Single/double EPDM / FKM composite O-rings; EPDM for water & food media, FKM for solvent & brine
Rated Pressure: PN16 standard; PN25 marine reinforced version optional
Operating Temperature: -20℃ ~ +180℃
Flow Channel: Full straight full-bore cavity, zero additional pressure loss, smooth inner wall to reduce residue adhesion
Structure Feature: Compact threaded T-body, snap-on top glass cover, fully disassemblable for paddle cleaning without pipeline cutting

3. Core Competitive Advantages

Compact Cast Stainless Steel Anti-Corrosion Body

Integral seamless casting eliminates internal dead zones, smooth inner surface avoids crystal and organic buildup. 316 grade upgrade delivers superior salt fog resistance for coastal and yacht piping.
Universal Internal Thread Quick Installation

Symmetric standard internal threads fit all common threaded pipe fittings, no flange or welding required, greatly shortening small branch pipeline construction time.
Quantitative Calibrated Swing Paddle Visual Feedback

Unlike simple impeller sight glasses, the weighted swing paddle displays approximate flow volume via printed scale, enabling operators to judge flow magnitude intuitively, not just on/off status.
Zero Pressure Loss Full-Bore Design

No protruding flow obstruction inside, original pipeline flow capacity fully retained, ideal for low-pressure loss micro circulation loops.
Chemical-Inert Swing Paddle Assembly

Stainless steel + PPS composite paddle resists acid, alkali and saltwater erosion, stable swing performance under long-term medium contact.
Snap-On Low-Maintenance Top Cover

Threaded lock top cover can be opened without removing the whole fitting, easy to take out paddle and flush limescale, fertilizer and chemical sludge.
Mini Space-Saving Layout

Small cylindrical threaded structure occupies minimal linear space, perfectly suitable for dense instrument racks, clean room small branch lines and compact yacht engine room piping.
Dual Redundant Anti-Aging Sealing System

Dual elastic sealing rings prevent medium leakage under frequent temperature and pressure fluctuations, long service life for continuous production.

4. Global Application Scenarios

Sanitary Food & Pharmaceutical Industry: Purified water branch circulation, beverage transfer small pipelines, cosmetic raw material micro delivery lines; stainless steel meets food contact hygiene standards.
Fine Corrosive Chemical Industry: Low-concentration acid/alkali solvent branch pipelines, electroplating small circulation loops, lab reagent delivery piping; inert wetted surface avoids metal ion contamination.
Precision Large-Scale Agriculture: Greenhouse nutrient solution branch irrigation pipelines, farm water supply sub-lines, fertilizer dosing auxiliary piping; anti-corrosion material resists agricultural chemical erosion.
Yacht & Coastal Marine Systems: Small ship auxiliary cooling circulation lines, coastal aquaculture low-salinity water branch piping, yacht fresh water circulation loops; 316 stainless steel withstands ocean salt fog corrosion.
Auxiliary Supplementary Fields: HVAC heating branch water lines, small solar hot water circulation pipelines, fire protection small branch clean water piping, industrial pure water pretreatment sub-equipment.

5. Customization Support

Material: Standard 304 stainless steel, upgrade to 316 marine anti-corrosion grade
Thread Standard: Custom BSPP, BSPT, NPT thread specifications
Pressure Grade: PN16 standard, PN25 high-pressure marine customized
Sealing Material: EPDM food grade / FKM chemical resistant grade optional
Brand & Packaging: Laser engrave customer LOGO, export neutral wooden case packaging; full material & pressure test certificates for bidding
Sizes: DN15, DN20, DN25, DN32, DN40, DN50 customizable

6. Factory Quality Control

All WF-BB11 series threaded sight indicators implement 100% full inspection before shipment, including hydraulic burst pressure test, thread sealing leakage test, salt spray long-cycle anti-corrosion test, paddle flow sensitivity test and cold-hot alternating aging test. Complete stainless steel material certificates, sanitary inspection reports and pressure vessel test documents can be provided for global project tender, marine platform audit and food factory compliance assessment.