NOTE: This disposition is nonprecedential.

United States Court of Appeals 

for the Federal Circuit ______________________ 

SOUTH-TEK SYSTEMS, LLC, POTTER ELECTRIC 

CO, LLC,

Appellants

v.

ENGINEERED CORROSION SOLUTIONS, LLC,

Appellee

______________________ 

2017-2297

______________________ 

Appeal from the United States Patent and Trademark 

Office, Patent Trial and Appeal Board in No. IPR2016-

00136.

______________________ 

Decided: September 20, 2018

______________________ 

 DAVID E. BENNETT, Coats & Bennett, PLLC, Cary, 

NC, argued for appellants. Also represented by EDWARD 

H. GREEN, III, BRANDEE NICOLE WOOLARD. 

 JASON E. STACH, Finnegan, Henderson, Farabow, 

Garrett & Dunner, LLP, Atlanta, GA, argued for appellee. 

Also represented by BENJAMIN AARON SAIDMAN. 

______________________ 
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Before DYK, O’MALLEY, and HUGHES, Circuit Judges.

HUGHES, Circuit Judge.

South-Tek Systems, LLC and Potter Electric Co, LLC 

filed a petition requesting inter partes review of the U.S. 

Patent No, 9,144,700 on four grounds for invalidity. The 

Patent Trial and Appeal Board instituted review of all 

claims in the ’700 patent, but on only two of the grounds 

raised. The Board then determined that the petitioners 

failed to establish that the challenged claims are unpatentable. We affirm the Board’s determination that the 

challenged claims are not unpatentable over the two 

grounds for invalidity that it considered. We remand, 

however, for the Board to consider whether those claims 

are unpatentable over the two non-instituted grounds.

I 

Engineered Corrosion Solutions, LLC owns the ’700

patent, which relates to a “dry pipe” fire protection sprinkler system. When not operating to suppress fires, sprinkler systems must prevent water from flowing through 

the system. “Dry pipe” systems accomplish this by filling 

the system’s pipes with a compressed gas that creates 

enough pressure to hold back a water source. When heat 

causes a sprinkler head to open, the compressed gas flows 

out of the system, reducing the pressure and allowing 

water to flow out as well. 

One difficulty associated with maintaining dry pipe 

sprinkler systems is preventing pipe corrosion. Many

factors affect whether and how quickly pipes deteriorate. 

Relevant here, residual water left in the pipes after 

system use or testing can accelerate corrosion. That

water may contain microbiological organisms that establish colonies in the pipes and create leaks through microbiological induced corrosion. The water, along with

oxygen trapped in the pipes, can also cause oxidative 

corrosion in pipes made of certain metals. 
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To combat these corrosion risks, the ’700 patent 

recites a sprinkler system that expels oxygen and water 

using compressed nitrogen. The Board found that it 

would have been obvious to use compressed nitrogen from 

a nitrogen generator in such a sprinkler system, but that 

the prior art did not disclose the claimed “vent” used to 

expel oxygen from the system. Thus, two limitations of 

the claimed sprinkler system are relevant for this appeal. 

First, the system requires a drum drip drain that enables 

water to exit the system. Second, the system requires a 

vent that allows gas, including oxygen, to exit. Claim 1 is 

representative:

A water-based fire protection system comprising: 

a dry pipe sprinkler system comprising at least 

one fusible sprinkler, a source of pressurized water, a piping network connected to the at least one 

fusible sprinkler, one or more drains, and a dry 

pipe valve coupling the source of pressurized water to the piping network, the dry pipe valve having a clapper, the piping network pitched toward 

the one or more drains, and the one or more drains 

including a drum drip; 

a nitrogen generator coupled to the piping network, the nitrogen generator operable to pressurize the piping network with nitrogen and 

maintain the clapper of the dry pipe valve in a 

closed position until the water-based fire protection system is actuated; and

at least one vent positioned within the piping network, the at least one vent operable to allow gas 

including oxygen displaced by the nitrogen to exit 

the piping network at a preset or adjustable limit 

while maintaining enough pressure within the 

system to prevent the clapper of the dry pipe 

valve from opening until the water-based fire protection system is actuated to thereby increase the 
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concentration of nitrogen and decrease the concentration of oxygen in the piping network to reduce or eliminate the rate of corrosion in the 

piping network. 

’700 patent col. 18 ll. 14–37 (emphases added). 

In November 2015, South-Tek Systems, LLC and 

Potter Electric Co, LLC (collectively, South-Tek) filed a 

petition requesting inter partes review of every ’700 

patent claim. South-Tek’s petition raised four grounds for 

invalidity, all of which were obviousness challenges based

on different combinations of four prior art references. 

Each ground relied on U.S. Patent No. 6,540,028 

(Wood). Wood discloses a “condensate drain for a dry pipe 

sprinkler system.” J.A. 836. The drain is a “normally 

closed control valve” that opens “at a predetermined air 

pressure between the system minimum and maximum 

pressures.” J.A. 837. When the drain opens, “condensed 

water, or air when water is not present, is discharged 

through the discharge nozzle until the air pressure drops 

to a predetermined level.” Id. This enables residual 

water to automatically exit the system as the air pressure 

cycles between its minimum and maximum levels. 

The petition also relied on a document published by 

Viking Corporation titled “Dry Pipe Sprinkler System” 

(Viking), U.S. Patent No. 7,322,423 (Ringer), and U.S. 

Patent No. 7,717,776 (Wagner). Viking discloses the 

components, operation, and maintenance of a typical dry 

pipe sprinkler system. The system’s components include 

a pipe system, a water source held back by compressed 

nitrogen, and a “two-valve drum drip” that functions as a 

drain. J.A. 828. Ringer similarly discloses a dry pipe 

sprinkler system. Wagner discloses the use of oxygen 

sensors to measure and control the oxygen level in a room 

to suppress fires. 
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The Board instituted review on Grounds 1 and 2 of 

South-Tek’s petition. Ground 1 alleged that claims 1–2 

and 5–9 were invalid as obvious over a combination of 

Wood, Viking, and admitted prior art. Ground 2 alleged 

that claims 3–4 were invalid as obvious over a combination of Wood, Viking, admitted prior art, and Wagner. 

The Board, however, declined to institute review on 

Grounds 3 and 4. Ground 3 alleged that claims 1–2 and 

5–9 were invalid as obvious over a combination of Wood, 

Ringer, and admitted prior art. Ground 4 alleged that 

claims 3–4 were invalid as obvious over a combination of 

Wood, Ringer, admitted prior art, and Wagner. 

In its final written decision, the Board upheld the 

validity of every challenged claim over Grounds 1 and 2. 

The Board also denied South-Tek’s post-trial motion to 

file supplemental information about the meaning of the 

claim term “drum drip.” 

South-Tek now appeals. We have jurisdiction under 

28 U.S.C. § 1295(a)(4)(A). 

II

We review the Board’s ultimate obviousness conclusions de novo and its underlying factual findings for 

substantial evidence. In re Giannelli, 739 F.3d 1375, 1379 

(Fed. Cir. 2014). The Board’s factual determinations 

include the scope and content of the prior art, differences 

between the prior art and the claimed invention, and 

whether a person having ordinary skill would have been 

motivated to combine the prior art. Intercontinental 

Great Brands LLC v. Kellogg N. Am. Co., 869 F.3d 1336, 

1343 (Fed. Cir. 2017). 

The Board found that Viking’s sprinkler system discloses most of the limitations recited by the claims, but 

that it fails to disclose the claimed “vent.” Recognizing 

this deficiency, South-Tek argued that Wood’s condensate 

drain could have been added to Viking’s system to satisfy 
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the vent limitation. The Board, however, determined (1) 

that Wood’s condensate drain could not function as a vent 

and (2) that a person of ordinary skill would not have 

been motivated to add Wood’s condensate drain to Viking’s system. 

The Board lacked substantial evidence for its finding 

that Wood’s condensate drain could not operate as a vent 

if added to Viking’s system. Rather than construe “vent,” 

the Board relied on the claims’ functional description of a 

vent as “operable to allow gas including oxygen displaced 

by the nitrogen to exit the piping network at a preset or 

adjustable limit while maintaining enough pressure 

within the system to prevent the clapper of the dry pipe 

valve from opening until the water-based fire protection 

system is actuated . . . .” ’700 patent col. 18 ll. 29–34. The 

Board then determined that South-Tek “offer[ed] no 

persuasive evidence that Wood’s condensate drain is 

operable to allow gas to exit the piping network at a 

present or adjustable limit while maintaining enough 

pressure” to hold back the water source. J.A. 29–30. 

But Wood explicitly describes its condensate drain as 

operating in this way. It offers the following example: 

An example of an application is a piping system 

which is normally pressurized with air. An air 

compressor is automatically set to cut in at 30 psi 

and cut out at 40 psi, thereby maintaining 30 to 

40 psi of air pressure at all times. The automatic 

drain device might be set to open above 35 psi and 

close when the pressure drops below 35 psi. Each 

time the compressor completes a 10-psi cycle, one 

half of the cycle will be automatically discharging 

condensed water or air. 

J.A. 837. In this application, the condensate drain allows 

gas, including oxygen, to exit the piping system. The 

drain opens at a preset limit of 35 psi and closes below 35 

psi to maintain sufficient pressure to hold back a water 
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source until the sprinkler system activates. This suffices

to satisfy the ’700 patent claims’ vent limitation. 

The Board’s observation that “Wood discloses that its 

fundamental objective is to drain condensed water,” 

rather than “balance pressures,” does not alter this analysis. J.A. 30. Regardless of its “fundamental objective,” 

Wood’s condensate drain operates just as the claimed 

vent. It is irrelevant that the prior art primarily used the 

drain for a different purpose. See KSR Int’l Co. v. Teleflex 

Inc., 550 U.S. 398, 420 (2007) (“[F]amiliar items may have 

obvious uses beyond their primary purposes . . . .”). 

Thus, the Board lacked substantial evidence for its determination that Wood’s condensate drain cannot operate 

as a vent.1

Nonetheless, the Board had substantial evidence for 

its finding that a person of ordinary skill would not have 

been motivated to combine Wood’s condensate drain with 

Viking’s sprinkler system. South-Tek’s petition argued 

that it would have been obvious “to add a vent operative 

to vent displaced oxygen while maintaining system pressure, as taught by Wood.” J.A. 92. But South-Tek failed 

to present any evidence that a person of ordinary skill 

would have been motivated to use Wood’s condensate 

drain as an air vent. Instead, South-Tek only argued that 

a person of ordinary skill would have been motivated to 

use Wood’s drain to allow water to drain from Viking’s 

system. Viking’s system already includes a drum drip 

drain that serves this purpose. Given the redundant 

functions of Viking’s drum drip and Wood’s condensate 

drain, the Board found a person of ordinary skill would 

1 Because we determine that Wood’s condensate 

drain satisfies the claims’ “vent” limitation, we need not 

reach South-Tek’s argument that the Board erred by 

implicitly adopting an improper construction of “vent.” 

 
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not have been motivated to add a condensate drain to 

Viking in addition to the system’s drum drip drain. 

South-Tek does not challenge the Board’s finding that 

there would not have been a motivation to add Wood’s 

automatic drain to Viking’s system. On appeal, SouthTek argues that a person of ordinary skill would have 

been motivated to substitute Wood’s condensate drain for 

Viking’s drain. Because Wood’s condensate drain automatically discharges water as a sprinkler system cycles 

between its minimum and maximum air pressures, 

South-Tek contends that it would have been viewed as an 

improvement over the Viking drains that had to be manually opened and closed. 

South-Tek, however, waived this substitution theory 

by failing to argue it in its petition. “[I]t is of the utmost 

importance that petitioners in the IPR proceedings adhere 

to the requirement that the initial petition identify ‘with 

particularity’ the ‘evidence that supports the grounds for 

the challenge to each claim.’” Intelligent Bio-Sys., Inc. v. 

Illumina Cambridge Ltd., 821 F.3d 1359, 1369 (Fed. Cir. 

2016) (quoting 35 U.S.C. § 312(a)(3)). The Board does not 

err by refusing to consider arguments improperly raised 

in a petitioner’s reply brief for the first time. Id. at 1369–

70. Here, the Board recognized that South-Tek’s petition 

only argued that Wood’s condensate drain could be added

to Viking, not that Wood’s drain could replace Viking’s 

drum drip drains. See J.A. 32. Thus, the Board did not 

err by declining to consider South-Tek’s new theory that a 

person of ordinary skill would have been motivated to 

substitute Wood’s drain for Viking’s drains. 

We are not persuaded by South-Tek’s argument that 

the Board should have understood the petition’s reference 

to “add[ing] a vent . . . as taught by Wood” to mean substituting Wood’s drain for Viking’s drains. Even setting 

aside the plain difference between addition and substitution, the claim chart in South-Tek’s petition confirms the 
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Board’s understanding of South-Tek’s arguments. That 

chart identifies Viking’s drum drip drain as satisfying the 

claims’ “one or more drains including a drum drip” limitation. The chart never suggests that Wood’s condensate 

drain, or any other element of Viking, could similarly 

satisfy that limitation. Thus, the claim chart makes clear 

that the obviousness theories in South-Tek’s petition did 

not contemplate replacing Viking’s drain. 

In sum, the Board had substantial evidence for its 

finding that a person of ordinary skill would not have 

been motivated to combine Wood and Viking. South-Tek 

does not challenge the Board’s rejection of the motivation 

to combine arguments made in its petition, instead relying exclusively on a new argument that the Board reasonably refused to consider. Thus, because South-Tek’s 

obviousness theories relied on Wood to supply the claimed 

“vent” limitation, the Board did not err in determining 

that none of the challenged claims would have been 

obvious over Grounds 1 and 2 of South-Tek’s petition. 

III

 South-Tek also argues that the Board erred by failing 

to construe the claim term “drum drip” and by denying 

South-Tek’s motion to file supplemental information 

about the meaning of “drum drip.” Neither argument has 

merit.

We review the Board’s ultimate claim construction de 

novo and any underlying factual determinations involving 

extrinsic evidence for substantial evidence. In re Cuozzo 

Speed Techs., LLC, 793 F.3d 1268, 1279–80 (Fed. Cir. 

2015). The Board, however, only needs to construe terms 

“that are in controversy, and only to the extent necessary 

to resolve the controversy.” Vivid Techs., Inc. v. Am. Sci. 

& Eng’g, Inc., 200 F.3d 795, 803 (Fed. Cir. 1999). We 

review the Board’s denial of motions to file supplemental 

information after an IPR has been instituted for abuse of 
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discretion. Ultratec, Inc. v. CaptionCall, LLC, 872 F.3d 

1267, 1271 (Fed. Cir. 2017). 

The Board did not err by declining to construe “drum 

drip.” South-Tek argues that such a construction is 

necessary to resolve the parties’ dispute over whether 

Wood’s condensate drain satisfies the claims’ drum drip 

limitation. The Board, however, rejected South-Tek’s 

obviousness theories because there would not have been a 

motivation to combine Wood and Viking. Accordingly, it 

was unnecessary for the Board to determine whether 

Wood’s condensate drain satisfied the claims’ drum drip 

limitation. 

For the same reason, the Board did not abuse its discretion by denying South-Tek’s motion to file supplemental information related to the meaning of drum drip. 

That information would have been irrelevant to the basis 

for the Board’s decision. 

IV

In light of the Supreme Court’s decision in SAS Institute, Inc. v. Iancu, 138 S. Ct. 1348 (2018), South-Tek also 

challenges the Board’s decision to institute review of the 

’700 patent claims on only two of the four grounds raised 

in South-Tek’s petition. We agree that remand is appropriate for the Board to address the non-instituted 

grounds. 

The Supreme Court explained in SAS “that the petitioner’s petition, not the Director’s discretion, is supposed 

to guide the life of” an IPR. Id. at 1356. The Court thus 

held that the Board cannot institute review of fewer than 

all of the claims that a petitioner challenges. Id. at 1359–

60. Since SAS, we have recognized that the Court’s 

reasoning also prohibits the Board from instituting review 

of fewer than all of the grounds that a petitioner raises. 

See PGS Geophysical AS v. Iancu, 891 F.3d 1354, 1359 
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(Fed. Cir. 2018) (“We will treat claims and grounds the 

same in considering the SAS issues currently before us.”). 

Here, the Board instituted review on Grounds 1 and 2 

of South-Tek’s petition, but declined to institute review on 

Grounds 3 and 4. SAS forecloses this type of partial 

institution. Although South-Tek did not challenge this 

partial institution before the Board, we find that waiver 

does not apply to South-Tek’s prompt remand request 

following the significant change in law brought about by 

SAS. See Adidas AG v. Nike, Inc., 894 F.3d 1256, 1258 

(Fed. Cir. 2018) (“In several cases since SAS, we have 

found . . . waiver inapplicable to a prompt remand request 

due to the significant change in the law.”); Polaris Indus. 

Inc. v. Arctic Cat, Inc., 724 F. App’x 948, 950 (Fed. Cir. 

2018) (“Polaris’s failure to challenge the Board’s partial 

institution before the Supreme Court’s issuance of SAS is 

therefore excused.”). Thus, remand is appropriate for the 

Board to address Grounds 3 and 4 of South-Tek’s petition. 

V 

Because the Board had substantial evidence to support its finding that a person of ordinary skill would not 

have been motivated to combine Wood and Viking, it did 

not err in determining that the ’700 patent claims would 

not have been obvious over the combinations of prior art 

identified in Grounds 1 and 2 of South-Tek’s petition. As 

a result, we affirm the Board’s determination that the 

’700 patent claims are not unpatentable over Grounds 1 

and 2. We remand, however, for the Board to consider 

whether those claims are unpatentable over the two noninstituted grounds. 

AFFIRMED AND REMANDED