WF-FQ11-05F,Products,Wenzhou WeiFeng Technology Co., Ltd.

1. Product Overview

WF-FQ11-05F brass external thread spring float ball sight flow indicator is a compact mini inline visual flow monitor independently developed by TechWF. It adopts solid forged brass square body, male thread + female thread asymmetric connection, built-in spring loaded red float ball and full transparent borosilicate sight window. It features small size, light weight, anti-rust brass alloy and intuitive floating ball flow feedback, widely used in HVAC heating, light industrial machinery cooling, low-corrosion fine chemical, greenhouse agriculture irrigation, yacht and coastal onshore light marine small-bore threaded pipeline systems.

This sight glass is integrally hot forged from high-quality H59 brass, with male external thread on one end and female internal thread on the other for flexible screw-on assembly. The vertical transparent full-view glass window contains a corrosion-resistant red float ball with return spring. When medium flows forward following the marked arrow, fluid buoyancy pushes the float ball upward to display normal flow; if flow stops or reverses, the spring pulls the ball back down to warn operators of pipeline cut-off or backflow. It provides reliable visual monitoring for equipment cooling loops, small dosing pipelines, branch irrigation lines and yacht auxiliary cooling circuits to prevent pump dry-running and heat exchanger overheating damage.

All finished units pass hydraulic burst pressure testing, brass anti-oxidation aging testing, thread sealing leakage testing and hot-cold alternating cycle verification before factory delivery, maintaining stable zero-leak operation under clean water, glycol, neutral light solvent and low-salinity coastal cooling water media globally.

2. Premium Technical Specifications

Body Material: Hot forged H59 brass alloy, surface sandblasted anti-oxidation treatment, rust-proof for neutral low-corrosion media
Connection Standard: Mixed thread structure (one end BSP/NPT male external thread, one end BSP/NPT female internal thread), available sizes DN8~DN40
Sight Window: Full vertical transparent thick borosilicate glass, 360° omnidirectional visible observation without blind angles
Indicator Core: Red PP float ball + stainless steel return spring, automatic reset when flow disappears
Sealing Assembly: Single-layer EPDM / FKM O-ring gaskets; EPDM for water & glycol media, FKM for neutral weak solvent
Nominal Working Pressure: PN16 standard grade; PN20 high-pressure reinforced version optional
Operating Temperature Range: -10℃ ~ +110℃
Flow Channel: Straight full-bore inner cavity, zero extra pressure drop, smooth inner wall reduces limescale and organic residue adhesion
Structural Feature: Square compact brass block body, asymmetric male/female thread, fully detachable glass window for float ball cleaning without pipeline disassembly

3. Core High-End Competitive Advantages

Solid Hot-Forged H59 Brass Square Anti-Rust Body

One-piece hot forging eliminates casting pores and internal dead zones; sandblasted brass surface resists oxidation and rust in humid indoor and coastal weak salt fog environments, no surface coating peeling issue. Compact square block structure saves installation space for dense small instrument pipelines.
Asymmetric Male + Female Mixed Thread Flexible Installation

One end male external thread, one end female internal thread, compatible with all standard threaded pipe fittings. No extra transition nipples required, supports arbitrary series connection of small branch pipelines to shorten construction cycle.
Full 360° Transparent Vertical Sight Window with Spring Float Ball

Full vertical glass enables observation from front, left and right sides; bright red float ball forms high contrast against clear glass for easy flow judgment from long distance. Built-in return spring prevents the float ball from floating away under reverse flow, automatically reset to bottom to remind staff of backflow or pipeline emptying.
Zero Pressure Loss Full-Bore Unobstructed Flow Path

No protruding throttle obstacles inside the cavity, fully retains original pipeline flow capacity, ideal for low-flow micro cooling circulation pipelines of machine tools and heating equipment.
Spring-Assisted Self-Reset Float Ball Assembly

Stainless steel spring has stable elasticity without fatigue deformation after long-term reciprocating movement; PP float ball resists neutral solvent and weak saltwater corrosion, sensitive to tiny flow changes without jamming.
Detachable Glass Window for Easy Maintenance

The transparent glass section can be disassembled separately without removing the whole sight indicator from pipelines, quickly take out float ball and spring to flush limescale, fertilizer sediment and oil sludge, convenient regular routine maintenance.
Ultra-Compact Mini Square Space-Saving Layout

Small square brass block design fits narrow equipment gaps, cabinet internal cooling pipelines and compact yacht engine room tiny branch piping where large stainless steel sight glasses cannot be mounted.
Simple Low-Failure Mechanical Structure

Only two moving parts (float ball + spring), no fragile swing paddles or dial components, ultra-low failure rate, stable continuous operation for 24-hour industrial equipment cooling loops.

4. Global Cross-Industry Application Scenarios

HVAC & Industrial Machinery Cooling Industry

CNC machine tool cooling threaded pipelines, injection molding machine auxiliary circulation lines, building heating small branch water pipes, solar hot water auxiliary circulation tubing; compact brass body matches narrow equipment internal installation gaps.

Low-Corrosion Light Fine Chemical Industry

Neutral water-based solvent small threaded branch pipelines, laboratory micro reagent delivery tubing, water-based coating low-pressure circulation loops; brass alloy is compatible with neutral non-acidic/alkaline media without metal ion contamination.

Large-Scale Precision Agriculture

Greenhouse nutrient solution branch irrigation threaded lines, farm small fertilizer dosing auxiliary pipelines, seedling watering micro sub-lines; spring float ball reliably displays fertilizer liquid flow state.

Yacht & Coastal Onshore Light Marine Systems

Small yacht auxiliary engine cooling threaded circulation lines, coastal aquaculture low-salinity water auxiliary piping, onshore oil field light cooling water sub-loops; brass anti-oxidation surface withstands weak coastal salt fog splash erosion.

Supplementary Auxiliary Fields

Industrial pure water pretreatment small branch pipelines, fire protection micro clean water threaded lines, compressor and hydraulic equipment auxiliary cooling circulation tubing.

5. Customized Engineering Support Service

Material Customization: Standard H59 forged brass, food-grade brass body optional for drinking water media
Thread Standard Customization: Custom BSPP, BSPT, NPT male/female mixed thread specifications
Pressure Grade Customization: PN16 standard, PN20 high-pressure reinforced variant
Sealing Material Matching: EPDM food grade / FKM solvent resistant grade optional
Brand & Packaging Customization: Laser engraved customer LOGO on brass square body, neutral anti-collision export wooden case packaging; complete material & pressure test certificates provided for tender documentation
Caliber Customization: DN8, DN10, DN15, DN20, DN25, DN32, DN40 non-standard threaded sizes available

6. Factory Premium Quality Control Standards

All WF-FQ11 series brass threaded float ball sight indicators implement mandatory 100% full inspection prior to shipment. Standard factory testing items include hydraulic burst pressure test, thread sealing leakage test, brass anti-oxidation aging test, float ball flow sensitivity test and cold-hot alternating cycle validation.

Complete brass 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.