Name: RCM Flo-Gage™ Ammonia Gas Flow Meters
Brand: RCM Industries
Availability: InStock

Question 1

Why can't I use a standard RCM meter on ammonia service?

Accepted Answer

Standard RCM Flo-Gage meters contain brass and bronze components. Ammonia — both liquid and gas — reacts aggressively with copper alloys including brass and bronze, causing stress corrosion cracking and rapid degradation. This creates a serious safety hazard. Option N provides a fully brass-free 316 Stainless Steel construction required for safe ammonia service.

Question 2

What does Option N include?

Accepted Answer

Option N specifies: 316 Stainless Steel body (brass-free), 316 SS bellows, EPR seals (compatible with ammonia), and a gasketed case for additional leak protection. All wetted components are free of copper alloys. This is the required configuration for any ammonia application.

Question 3

Are EPR seals required for ammonia, or can I use Buna-N or Viton?

Accepted Answer

EPR (Ethylene Propylene Rubber) seals are standard and required for ammonia service. Buna-N seals are not compatible with ammonia and will degrade rapidly. Viton seals also have limited compatibility with ammonia — EPR is the correct choice. Option B2 (Teflon seals) is available as an alternative for applications requiring the highest chemical resistance.

Question 4

Can the ammonia meter be used for both liquid and gas ammonia?

Accepted Answer

The standard ammonia product page covers gas ammonia service. Liquid ammonia service is also available — it requires the same brass-free 316SS construction with EPR seals and gasketed case, but the meter is calibrated for liquid rather than gas. Contact Northeast Controls and specify whether your application is liquid or gas ammonia.

Question 5

What are the typical applications for ammonia flow meters?

Accepted Answer

Common applications include industrial refrigeration systems (cold storage, food processing, ice rinks), fertilizer production and distribution, manufacturing of plastics, textiles, and pesticides, refinery operations (neutralizing crude oil acid), and distillation plants. Ammonia is one of the most widely used industrial chemicals worldwide.

Question 6

What flow ranges are available for ammonia gas service?

Accepted Answer

Gas ammonia flow ranges span from 40 SCFH (1 Nm³/h) in ½″ meters up to 20,000 SCFM (60,000 Nm³/h) in 8″ meters. Pipe sizes from ¼″ to 8″ are available. For low flow rates below the standard range, Option ES (available on ½″ 7000 Series only) provides ranges from 40 to 400 SCFH.

Question 7

What is the maximum pressure and temperature rating?

Accepted Answer

Standard ammonia meters are rated to 180 psig and 212°F (100°C). Optional high-pressure construction increases the rating to 400 psig. Extended temperature options allow operation down to -30°F standard, or -80°F with optional construction. Specify your operating conditions when ordering.

Question 8

What connection styles are available?

Accepted Answer

Series 7000 meters use threaded FNPT connections from ¼″ to 3″. Series 8000 wafer-style meters mount between 150 or 300 class flanges from ½″ to 8″. Both series are available with Option N (brass-free 316SS for ammonia service).

Question 9

Can I add a remote readout to an ammonia meter?

Accepted Answer

Yes. Option R3 provides a remote readout with a 316 SS mechanical indicator, separating the display from the process connection. This is useful when the meter is installed in a location that is difficult to read directly, or when the ambient temperature at the meter location is outside the indicator's operating range.

Question 10

Is a transmitter (4-20 mA output) available on ammonia meters?

Accepted Answer

Yes. Transmitter options (W, W2, W3, RW3) are available on ammonia meters, subject to material compatibility. Confirm your full option combination with Northeast Controls when ordering, as some option combinations may have restrictions.

Question 11

What straight pipe is required upstream of an ammonia meter?

Accepted Answer

Provide a minimum of 10 pipe diameters of straight pipe upstream of the meter. Avoid elbows, tees, and control valves immediately upstream. Install control valves downstream of the meter whenever possible to maintain a stable flow profile at the meter.

Component	Standard	Options
Housing	Polycarbonate	Aluminum
Body	316 SS	n/a
Bellows	316 SS	—
Seals	EPR	n/a
Crystal	Polycarbonate	Glass / Plastic
Gear Movement	316 SS	—

Specification	Standard	Optional
Accuracy	±3% F.S.	—
Repeatability	±1% F.S.	—
Maximum Pressure	180 psig	400 psig
Minimum Pressure	10 psig	10 psig
Maximum Temperature	212°F	350°F
Minimum Temperature	-30°F	-80°F

Section	Description
Pipe Size	Meter size (¼″ to 8″)
Series	7000 = Threaded (FNPT) · 8000 = Wafer (flanged)
Material	Bronze (1) · Monel (2) · Stainless Steel (3)
Flow Direction	L, R, VUR, VUL, VDR, VDL
Flow Rate	Full-scale SCFM — refer to flow range tables
Options	Option codes — refer to options table

Code	Material
1	Bronze
2	Monel
3	Stainless Steel (SST)

Code	Description
L	Right to Left
R	Left to Right
VUR	Vertical Up Flow, Dial Right
VUL	Vertical Up Flow, Dial Left
VDR	Vertical Down Flow, Dial Right
VDL	Vertical Down Flow, Dial Left

Ammonia (Gas) Flow Meters

Features & Benefits

Typical Applications

Principle of Operation

Specifications — Materials of Construction

Performance & Ratings

Model Number System

Material Codes

Flow Direction Codes

Available Pipe Sizes

Table of Options

Standard Flow Ranges — Series 7000 & 8000

Low Flow Rates — Option ES

Pressure Drop Characteristics

Dimensions — Face-to-Face Length

Ammonia Flow Meter FAQ

Safety & Material Requirements

Application & Sizing

Installation & Options

Select a Product

Code	Description
B	EPR Seals
B2	Teflon Seals
E	Non-Standard Flow Rate
ES	Low Flow Rate (Below 2 GPM)
F	Aluminum Housing with Plastic Dial Crystal
F2	Aluminum Housing with Glass Dial Crystal
G	Custom Scales and Dials
I	Compressed Gas Service
P	Panel Mount
R3	Remote Readout, 316 SS (Mechanical Indicator)

Nominal Size	Series 7000 (Threaded)	Series 8000 (Wafer)
¼″	5.95″ (151mm)	n/a
½″	5.95″ (151mm)	6.62″ (168mm)
¾″	5.95″ (151mm)	7.06″ (179mm)
1″	6.07″ (154mm)	7.25″ (184mm)
1½″	6.39″ (162mm)	7.81″ (198mm)
2″	6.80″ (172mm)	8.00″ (203mm)
2½″	n/a	8.54″ (217mm)
3″	7.48″ (190mm)	8.87″ (225mm)
4″	n/a	9.95″ (252mm)
5″	n/a	10.36″ (263mm)
6″	n/a	11.05″ (280mm)
8″	n/a	12.30″ (311mm)

SCFM	Nm³/h
10	15
20	30
30	50

SCFM	Nm³/h
10	15
20	30
30	50
40	80
60	100

SCFM	Nm³/h
60	100
100	150
150	200
200	300

SCFM	Nm³/h
150	250
200	400
300	500
400	600