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Sight Flow Indicators

NAC-Series Flow Sight Glass Gauge

Threaded liquid-flow observation, with or without a ball

The NAC-Series provides a clear view of liquid in small pipes through a borosilicate glass tube. Female inlet and outlet connections are available in G (BSP) or NPT.

NAC Brass Body product photographBrass Body
NAC SS316 Body product photographSS316 Body

Technical data

Materials

Body
Brass, SS316, Hastelloy C-276, Monel 400 or Duplex S31803
Tube housing
Borosilicate glass
O-ring
Viton
Thread connection
Brass or SS316
Ball
PTFE
Optional spring
SS316L only
Protection tube
Brass for body B; SS316 for S; SS316L for H, M4 and Du

Operating limits and connections

Maximum pressure
10 bar
Maximum temperature
70°C
Connection sizes
1/4, 3/8 or 1/2 in; other sizes on request
Connection threads
G (BSP) or NPT female; other connections on request
Without ball
Flow in any direction
With ball
Bottom-to-top flow only

Dimensions and flow direction

Each configuration groups its drawings, flow direction and dimensions together. Linear dimensions are in millimetres; D is the connection thread size.

NAC — Without Ball

NAC without-ball front and section views with L, AF, D, d and E dimensions and protection tube callout
Without Ball — Front and section views
NAC without-ball gauge in four permitted flow orientations
Without Ball — Any flow direction
Without Ball dimensions
SizeL (mm)AF (mm)D (thread)d (mm)E (mm)Weight (approx. kg)
1/4 in70191/4 in5120.085
3/8 in70273/8 in8120.17
1/2 in80321/2 in1215.50.28

NAC — With Ball

NAC with-ball front and section views showing PTFE ball, optional SS316L spring, protection tube and dimension letters
With Ball — Front and section views
NAC with-ball gauge with upward flow arrows
With Ball — Bottom to top only
With Ball dimensions
SizeL (mm)AF (mm)D (thread)d (mm)E (mm)Weight (approx. kg)
3/8 in80323/8 in8120.31
1/2 in80321/2 in815.50.31

The PDF lists with-ball dimensions for 3/8 and 1/2 in only. Other sizes or configurations require confirmation.

NAC special type with M18 x 1.5 male outlet and 3/8 BSP female inlet
Special Type — On requestOutlet: M18 × 1.5 male. Inlet: 3/8 in BSP female. Please consult Sightflow for this special type.

Ordering information

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The ordering chart lists all three standard sizes, but the with-ball dimension table covers only 3/8 and 1/2 in. Confirm any other with-ball configuration before ordering.

Specifications are general selection guidance. Confirm materials, connection standards, operating temperature and pressure with Sightflow before placing an order.