CENTRAL GB - User Manual

Manufactured by: Central Sprinkler Company
451 North Cannon Avenue, Lansdale, Pennsylvania 19446
Product
Description
GB & GB-QR Dry Pendent
No. 5-5.0
Model: GB & GB-QR Dry Pendent
Style: Flush, Recessed & Extended
Wrench:
Offset (flush & extended) Part #1068
Universal
(recessed pendent) Part #1069
Orifice Size:
1
⁄2" (12.7 mm)
K-Factor: See K-Factor Table on page 2.
Thread Size 1" (25 mm) N.P.T.
*Temperature Ratings & Bulb Color:
135°F/57°C Orange
155°F/68°C Red
175°F/79°C Yellow
200°F/93°C Green
250°F/121°C Blue
286°F/141°C Blue
360°F/182°C Purple
* Refer to chart below for specific temperature
Listings.
Approvals: U.L., U.L.C.
Technical
Data
The Model GB and GB-QR Dry
Pendent Glass Bulb Sprinklers are
designed for use in special applica-
tions such as freezing environments
or in conditions where sediment or
foreign materials might accumulate in
ordinary drop nipples. They are
available in standard response (5mm
bulb) or quick response (3mm bulb).
A significant installation feature for
the extended version is the built in 3"
(76.2 mm) of adjustment. This allows
installation of common lengths and
can compensate for field variations.
A larger wrench boss allows the
sprinkler to be installed into the
branchline tee using a sprinkler
wrench. This allows easy installation
in “hard” ceilings such as sheet rock
as the barrel of the dry pendent
would be inaccessible.
The Model GB and GB-QR Dry
Pendents have a maximum adjust-
ment of ±1
1
⁄2" (38.1 mm) in the
extended version, allowing ease of
field installation and ordering. Also,
the Model GB dry pendent is avail-
able recessed or flush for situations
that require a more aesthetic appear-
ance.
Operation: The glass bulb
capsule operating mechanism
contains a heat-sensitive liquid that
expands upon application of heat. At
the rated temperature, the frangible
capsule ruptures, thereby releasing
the orifice seal. The sprinkler then
discharges water in a pre-designed
spray pattern to control or extinguish
the fire.
GB & GB-QR Dry Pendent
1-98
Standard and Quick Response
Flush, Recessed and Extended
Glass Bulb Sprinkler
GB Flush & Extended GB Recessed GB-QR Flush & Extended GB-QR Recessed
135, 155, 175, 135, 155, 175 135, 155, 175, 135, 155, 175
200, 286, 360 200 200, 250 200
U.L. & U.L.C. Temperature Listings
Maximum Working Pressure:
175 psi (12.1 bar)
Factory Hydro Test: 100% at
500 psi (34.5 bar)
Standard Finishes:
Sprinkler: brass, chrome plated,
white
Escutcheon: brass, chrome plated
and white painted
1
⁄2
"
(12.7 mm)
Orifice
Dry Pendent
Automatic
Sprinklers
Corrosion-Resistant Coatings (U.L.
Only) : white and black painted
Ceiling Opening: 2 1/4" (57.2 mm)
OBSOLETE

Summary

Product Description

Operation

Describes the glass bulb capsule operating mechanism and its function.

Technical Data

Temperature Ratings and Bulb Color

Lists temperature ratings and corresponding bulb colors.

Ordering Length for Dry Pendent Heads

Flush Type Ordering Length

Details 'A' dimension measurement for flush types.

Recessed Type Ordering Length

Details 'A' dimension measurement for recessed types.

Extended Type Ordering Length

Details 'A' dimension measurement for extended types.

Dry Pendent Design Guidelines

Determine K-Factor Length

Steps to determine K-factor length based on sprinkler type.

Determine K-Factor from Table

How to find the K-factor using the provided table.

Use K-Factor in Calculations

Application of K-factor in branchline calculations.

Design Data

Design Requirements

Standard application requirements for GB/GB-QR sprinklers.

Installation

Installation Requirements

General requirements for installing GB/GB-QR sprinklers.

Installation Sequence

Step-by-step instructions for installing the sprinkler.

Care & Maintenance

Handling and Storage

Guidelines for careful handling and proper storage.

Sprinkler Alterations

Prohibits painting, coating, or altering sprinklers.

Maintenance Responsibilities

Owner's responsibility for operating condition and inspections.

System Inspection

Advises regular inspection by qualified services.

Post-Activation Procedures

Procedures for replacing operated or damaged sprinklers.

Discharge Pattern Integrity

Ensures nothing obstructs the sprinkler's discharge pattern.

Ordering Information

System Shutdown and Replacement

Steps for removing system from service and replacing units.

Post-Activation System Repair

Ensures systems are repaired and returned to service after activation.

Guarantee and Warranty

Details the company's repair/replacement warranty.

How to Order

Specifies information needed when placing an order.

Availability and Service

Information on product availability and how to contact for service.

Overview

1. Function Description
2. Important Technical Specifications
3. Usage Features
4. Maintenance Features

The Central GB & GB-QR Dry Pendent Sprinkler is an automatic sprinkler designed for specialized applications, particularly in environments prone to freezing or where sediment and foreign materials might accumulate in standard drop nipples. These sprinklers are available in both standard response (featuring a 5mm glass bulb) and quick response (with a 3mm glass bulb) versions.

Function Description:

The core of the sprinkler's operation lies in its glass bulb capsule, which contains a heat-sensitive liquid. Upon exposure to heat at its rated temperature, this liquid expands, causing the frangible capsule to rupture. This action releases the orifice seal, allowing water to discharge in a pre-designed spray pattern to control or extinguish a fire. The dry pendent design is specifically engineered to prevent water from accumulating in the drops leading to the sprinklers. This is achieved through a fitting that extends into the branch line, positioning the plug above the water line. This design ensures that even if residual water is present, the sprinkler can operate without the risk of freezing.

Important Technical Specifications:

• Model: GB & GB-QR Dry Pendent
• Style: Flush, Recessed & Extended
• Orifice Size: 1/2" (12.7 mm)
• Thread Size: 1" (25 mm) N.P.T.
• Maximum Working Pressure: 175 psi (12.1 bar)
• Factory Hydro Test: 100% at 500 psi (34.5 bar)
• Standard Finishes:
  • Sprinkler: Brass, chrome plated, white
  • Escutcheon: Brass, chrome plated and white painted
• Corrosion-Resistant Coatings (U.L. Only): White and black painted
• Ceiling Opening: 2 1/4" (57.2 mm)
• Temperature Ratings & Bulb Colors:
  • 135°F/57°C: Orange
  • 155°F/68°C: Red
  • 175°F/79°C: Yellow
  • 200°F/93°C: Green
  • 250°F/121°C: Blue
  • 286°F/141°C: Blue
  • 360°F/182°C: Purple
• U.L. & U.L.C. Temperature Listings:
  • GB Flush & Extended: 135, 155, 175, 200, 286, 360
  • GB Recessed: 135, 155, 175, 200
  • GB-QR Flush & Extended: 135, 155, 175, 200, 250
  • GB-QR Recessed: 135, 155, 175, 200
• K-Factor Table (Length to K-Factor (metric)):
  • 2 1/2" (63.5 mm) to less than 10" (76.4 mm): 5.3 (76.4)
  • 10" (254.1 mm) to less than 17" (75.0 mm): 5.2 (75.0)
  • 17" (447.7 mm) to less than 25" (73.5 mm): 5.1 (73.5)
  • 25" (641.4 mm) to less than 32" (72.1 mm): 5.0 (72.1)
  • 32" (831.9 mm) to less than 40" (70.7 mm): 4.9 (70.7)
  • 40" (1025.5 mm) to less than 48" (1219.2 mm): 4.8 (69.2)

Usage Features:

• Installation Flexibility: The extended version offers a significant installation advantage with a built-in 3" (76.2 mm) of adjustment. This feature accommodates common lengths and compensates for field variations, simplifying installation.
• Adjustability: The extended Model GB and GB-QR Dry Pendents provide a maximum adjustment of ±1 1/2" (38.1 mm), facilitating easier field installation and ordering.
• Aesthetic Options: The Model GB dry pendent is available in recessed or flush styles for situations demanding a more aesthetic appearance.
• Wrench Boss: A larger wrench boss allows the sprinkler to be installed into the branchline tee using a standard sprinkler wrench. This is particularly useful for "hard" ceilings like sheet rock where the barrel of the dry pendent would be inaccessible.
• K-Factor Determination: The K-factor for the sprinkler is determined based on its length, which varies depending on whether it's a flush, recessed, or extended model. The K-factor length is calculated by adding a specific offset to the "A" dimension (measured from the face of the tee to the finished ceiling).
• Ordering Length: For flush models, the "A" dimension is ordered to the nearest 1/4" (6.4 mm) with a minimum of 2" (50.8 mm). For recessed models, the minimum "A" dimension is 2 1/8" (54.6 mm) with an adjustment of ±3/16" (4.8 mm). For extended models, if "A" is less than or equal to 3 1/4" (82.6 mm), total adjustment is 1 1/2" (38.1 mm) (±3/4" (19.1 mm) from midpoint), ordered to the nearest 1/4" (6.4 mm) with a minimum "A" of 0". If "A" is greater than 3 1/4" (82.6 mm), total adjustment is 3" (76.2 mm) (±1 1/2" (38.1 mm) from midpoint), ordered to the nearest 1/4" (6.4 mm) with a minimum "A" of 3 1/4" (82.6 mm).

Maintenance Features:

• Handling and Storage: Sprinklers must be handled carefully, not transported or stored where ambient temperatures exceed 100°F/38°C. They should be kept in a dry, cool location in their original shipping package for optimal results.
• Damage Prevention: Never install sprinklers that have been dropped, visibly damaged (e.g., cracked glass bulb, loss of liquid), painted, coated, plated, or altered from their manufactured condition, as this can impair proper function and voids any warranty. Damaged or altered sprinklers must be replaced.
• Installation Best Practices: Install sprinklers after piping is in place to prevent mechanical damage. Ensure the correct model, style, orifice size, and temperature rating are used.
• System Testing: Upon completion of installation, the system must be tested according to recognized standards.
• Leak Resolution: In case of a thread leak, the unit should be removed, new pipe joint compound or tape applied, and then reinstalled.
• Regular Inspections: The owner is responsible for the proper operating condition of all fire protection devices. NFPA standard 25 provides guidelines for inspection, testing, and maintenance. Local Authorities Having Jurisdiction may impose additional requirements. Regular inspections by a qualified service are advisable, with frequency depending on accessibility, atmosphere, water supply, and site activity.
• Replacement Policy: Do not attempt to reassemble or reuse an operated sprinkler. Replace any sprinkler exhibiting corrosion or damage with new sprinklers of the same orifice, style, and temperature rating.
• Obstruction Prevention: Nothing should be hung or attached to the sprinkler unit that could disrupt the discharge pattern. Obstructions must be removed, and if construction changes alter the original configuration, additional sprinklers may be needed to maintain protection.
• Post-Activation Procedures: After a system activation, it must be repaired and returned to service immediately. The entire system should be inspected for damage, and any sprinklers subjected to corrosive elements or excessive temperatures should be inspected and replaced if necessary.
• Warranty: Central Sprinkler Company offers a one-year warranty, repairing or replacing any products found to be defective in material or workmanship from the date of shipment.

CENTRAL GB Specifications

General

Brand	CENTRAL
Model	GB
Category	Irrigation System
Language	English