King Instrument Company provide exceptional performance in a wide range of industrial, commercial and specialty applications.

King Instrument company's product line has grown to satisfy the demands of almost any variable area flowmeter application.

Flow meters from the King Instrument Company provide exceptional performance in a wide range of industrial, commercial and specialty applications. King Instruments’ product line has grown and expanded to satisfy the demands of almost any variable area flowmeter application.

King Instruments offers more styles, sizes, features and options to satisfy all your rotameter requirements.

King Instrument Company opened its doors in 1983 with one major goal: to produce the finest group of rotameters ever sold. King Instrument Company has changed over the years, running two shifts and utilizing the most sophisticated computer controlled machinery. King Instrument Company currently calls its home a 46,000 square foot facility in Garden Grove, California.

The Harrington Difference
Providing over 60 years of exceptional service

Harrington is a leading King Instrument distributor. Call our toll-free number at 1-800-213-4528 and you will be connected to a live person – not a recording. You can also use the contact form below for any questions regarding our full line of King Instrument products.

King Rotameters Provide Flow Measurement Assurance

King Instrument Company offers a wide variety of low and high flow rate rotameters based on your measurements and applications. King’s focus is on using proven technology and longstanding methods to build the most accurate, versatile, and economical rotameters possible. This specialization has allowed King to be a customer-focused provider of one of the most comprehensive lines of standard and specialized variable area flowmeters anywhere in the world today.

Series 7100 Flowmeter

The King Instrument 7100 series flowmeter all stainless steel construction is suitable for low-flow, high-pressure applications. Series 7750 offers the following scale ranges; 0.6 to 25.0 GPH, 2.4 to 95 LPH, 1.0 to 120.0 SCFH and 28.3 to 3400 SLPH. Inlet and outlet fittings are offered in 1/4″ 316L stainless steel female pipe threaded connections. Accuracy is ± 5% of full scale flow, turndown is 10:1 and repeatability is 1%. Series 7100 has multiple o-ring material options, scale options and valve options.

Series 7200 Flowmeter

The King Instrument 7200 series flowmeter is a general purpose flowmeter with vertical connections from 3/8″ to 2″ NPT. Series 7200 offers the following scale ranges; 1.0 to 200.0 GPM and 4.0 to 245.0 SCFM. Inlet and outlet fittings are offered in PVC (standard) with optional 316 stainless steel, brass and aluminum connections. Accuracy is ± 3% to 6% of full scale flow, turndown is typically 10:1 (some model variations may differ). Series 7200 has an EPR O-ring with optional Buna-N and Viton® offerings.

Series 7310 Flowmeter

The King Instrument 7310 series flowmeter has an economical 304 stainless steel case with a molded polysulfone metering tube for lighter duty applications where a case enclosed meter is preferred. Series 7310 offers the following scale ranges; 0.5 to 100 GPM with Teflon® float (water), 1.5 to 160 GPM (water) with metal float and 6.1 to 33 SCFM (air). Accuracy is ± 3% of full scale flow, ± 5% of full scale flow for 120 & 150 GPM metal floats and ± 6% of full scale flow for Teflon® floats. 

Series 7330 Flowmeter

The King Instrument 7330 series flowmeter is excellent for applications where no metal is preferred. Series 7330 offers the following scale ranges; 0.5 to 100 GPM with Teflon® float (water) and 1.5 to 160 GPM (water) with metal float. Accuracy is ± 3% of full scale flow, ± 5% of full scale flow for 120 & 150 GPM metal floats and ± 6% of full scale flow for Teflon® floats. Series 7330 has a standard Viton® O-ring with optional Buna-N, EPR and Kalrez® offerings.

Series 7430 Flowmeter

The King Instrument series 7430 flowmeter is available in both 65mm and 150mm scales with your choice of 1/4″ or 1/8″ FPT connections. Fitting materials offered are 316L stainless steel standard, with optional PVC, PVDF and Hastelloy® C. The internal components are 316L stainless steel standard with optional black glass, sapphire, carboloy and tantalum. The metering tube is borosilicate kinglass. The O-rings are Viton® standard with optional Buna-N, EPR and Kalrez® offerings. Series 7430 offers the following scale ranges; 0.56 to 1800 cc/min (water) and 54 to 70000 cc/min (air). 

Series 7450 Flowmeter

The King Instrument series 7450 flowmeter is a side plate style meter with either a 75mm (3″) or 150mm (6″) borosilicate glass tube and 316L stainless steel or brass connections. This meter is also available with PVC ends and Hastelloy® C-276 construction for greater chemical resistance. Series 7450 scale ranges; 0.48 to 7.4 GPM and 2 to 20 SCFM. Connection size for Series 7450 is a 3/8″ female pipe thread, designed to install horizontally. Internal components: 316L stainless steel; fitting material options are Brass or 316L stainless steel. O-rings are Viton® standard with optional Buna-N, EPR or Kalrez®. 

Series 7459 Flowmeter

The King Instrument series 7459 flowmeter is a side plate style meter that features a 250 mm scale, borosilicate glass tube, aluminum side plates and a polycarbonate shield. The connections are vertical 316L stainless steel female pipe thread. Connection sizes available are 1/2″, 3/4″, 1″ and 1-1/2″. The internal components are 316L stainless steel and the O-rings are Viton® standard with optional Buna-N, EPR and Kalrez® offerings. Series 7459 offers the following scale ranges; 0.22 to 100 GPM and 0.9 to 350 SCFM. Accuracy is ± 2% of full scale flow, turndown is 10:1 and repeatability is 0.5%.

Series 7460 Flowmeter

The King Instrument series 7460 flowmeter offers an economical 304 stainless steel case, vertical female pipe thread connections and a 75 mm glass tube. Connection sizes available are 1/2″ and 1″. The internal components are 316L stainless steel; optional Hastelloy® C-276. The O-rings are Viton® standard with optional Buna-N, EPR and Kalrez® offerings. Scale ranges: 0.5 to 25 GPM and 2.0 to 14 SCFM. Accuracy is ± 5% of full scale flow, turndown is 10:1 and repeatability is 1%. The case is 304 stainless steel with a polycarbonate shield and the metering tube is borosilicate kinglass.

Series 7470 Flowmeter

The King Instrument series 7470 flowmeter offers value and versatility with a 304 stainless steel case, vertical or horizontal NPT or flange connections and a 127 mm scale glass tube. Connection sizes: 3/4″ and 1-1/2″ NPT or 1/2″, 1″ and 1-1/2″ flange. Fitting materials offered are 316L stainless steel standard; PVC optional (vertical connections only). Internal components are 316L stainless steel standard with optional Hastelloy® C-276. The O-rings are Viton® standard with optional Buna-N, EPR and Kalrez® offerings. The case is 304 stainless steel with a polycarbonate shield and the metering tube is borosilicate kinglass.

Series 7480 Flowmeter

The King Instrument series 7480 flowmeter has a 250 mm (10″) scale, economical glass tube and 304 stainless steel case. Vertical or horizontal NPT or flange connections offer installation versatility. 316L stainless steel or PVC connections are available in either 3/4″ and 1-1/2″ NPT sizes or 1/2″, 1″ or 1-1/2″ flange sizes. The internal components are 316L stainless steel standard with optional Hastelloy® C-276. The O-rings are Viton® standard with optional Buna-N, EPR and Kalrez® offerings. The case is 304 stainless steel with a polycarbonate shield and the metering tube is borosilicate kinglass. 

Series 7510 Flowmeter

The King 7510 and 7511 series are a low cost and economical acrylic tube variable area flowmeter offering a direct reading flow scale. Scales have a white screen printed back for easier readability. All internal components are 316L stainless steel with a standing fitting material of PVC with 316L stainless steel and brass an option. Fittings are available in female NPT with a vertical connection. EPR O-Rings are standard with an option of Buna N or Viton®. Flow scales are available in five sizes with a choice of 50mm, 65mm, 100mm, 127mm and 250mm. Repeatability also varies by flow scale size, from 0.5% to 3%. 

Series 7520/7530 Flowmeter

The King Instrument 7520 and 7530 series flowmeters are precision machined from durable cast acrylic stock and are available in a variety of scales for increased accuracy and repeatability; these range from 50 mm (2″) to 250 mm (10″). Series 7520/7530 have 316L stainless steel internal components. The standard fitting material is PVC (brass for 2C block size) with optional 316L stainless steel or brass. All connections are either male or female NPT. EPR is the standard O-ring with optional Buna-N, Viton® and Kalrez® available. Series 7520/7530 offers the following scale ranges; 7 GPH to 20 GPM and 2.6 SCFH to 60 SCFM. 

Series 7610 Flowmeter

The King Instrument series 7610 flowmeter features fully enclosed 127mm (3″ )scale, borosilicate glass metering tube with 304 stainless steel case. Series 7610 offers the following scale ranges; 0.25 to 116 GPM and 1 to 245 SCFM. The line-line female pipe thread connection sizes available for Series 7610 are; 1/2″, 1″ and 2″. The internal components are 316L stainless steel or Hastelloy® C-276. The fitting material options are 316L stainless steel or PVC. O-rings are Viton® standard with optional Buna-N, EPR or Kalrez®. Accuracy is ± 3% of full scale flow. Optional alarm with latching Reed switch available. Series 7610 conforms to ISA RP 16.6.

Series 7650 Flowmeter

The King Instrument series 7650 flowmeter is chemically resistant and is suitable for a wide range of chemical and corrosive applications. The 7650 flowmeter features a borosilicate glass tube meter, a clear polycarbonate shield and a 304 stainless steel tie road frame. Series 7650 offers the following scale range; 0.25 to 26 GPM. Series 7650 offers a 1″ vertical female pipe thread connection and an 80mm (3″) or 127mm (5″) scale. The internal components are 316L stainless steel or Hastelloy® C-276. The fitting material options are PVC or CPVC. O-rings are Viton®, Buna-N, EPR or Kalrez®. Accuracy is ± 3% of full scale flow for 80mm scale and ± 5% for 127mm scale. 

Series 7710 Flowmeter

The King Instrument 7710 series flowmeter is an all stainless steel meter that utilizes a float and tapered tube design which offers longer, more linear scales, better pointer stability and 40% greater accuracy than competitively priced products. A 4-20mA transmitter option adds to it’s versatility. Series 7710 offers the following scale ranges; 33 GPH to 450 GPM and 4 to 100 SCFM. The standard O-ring is Viton® with Buna-N, EPR and Kalrez® options available. Inlet and outlet fittings are offered in either flange or female NPT options. Accuracy is ± 3% of full scale flow, turndown is 10:1 and repeatability is 1%.

Series 7720 Flowmeter

The King Instrument 7720 series flowmeter offers chemical resistance with it’s Type 1, Grade 1 PVC tube meter and fitting. It’s dial type display makes measuring opaque fluids simple. Series 7720 offers the following scale range; 33 GPH to 450 GPM. Internal components are C-276 Hastelloy®. The standard O-ring is Viton® with Buna-N, EPR and Kalrez® options available. Inlet and outlet fittings are offered in either flange or female NPT options. Accuracy is ± 3% of full scale flow, turndown is 10:1 and repeatability is 1%. Maximum temperatures are available up to 54°C with maximum operating pressures available up to 10 bar.

Series 7750 Flowmeter

The King Instrument 7750 series flowmeter has an all stainless steel welded construction eliminating the need for o-rings. The float and tapered tube design provides longer, more linear scales and an optional 4-20mA transmitter adds to its versatility. Series 7750 offers scale ranges; 33 GPH to 16.5 GPM and 2.2 SCFM to 76 SCFM. Inlet and outlet fittings are stainless steel flanges offered in either 150# or 300#. Accuracy is ± 3% of full scale flow, turndown is 10:1 and repeatability is 1%. Scales are available in any volumetric unit.

Series 7910 Flowmeter

The King Instrument series 7910 flowmeter offers 70 flow ranges in 7 tube sizes. Dual port connections (both horizontal and vertical on each end) allow for a variety of installation options. Standard connections are female pipe thread in 1/2″, 1″, 1-1/2″ and 2″ sizes; flange connections also available. Scale ranges; 0.22 to 132 GPM and 0.9 to 350 SCFM. The tube scale is 250mm (10″), is made of Borosilicate Kinglass, has a 304 stainless steel case and a polycarbonate shield. O-rings are Viton® standard with optional Buna-N, EPR or Kalrez®. 

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Call our toll-free number at 1-800-213-4528 and you will be connected to a live person – not a recording. You can also use the contact form above for any questions regarding King Instrument products.